dotemacs

README.md (54992B)

---

 # Emacs Markdown Mode
 [![NonGNU ELPA badge][nongnu-elpa-badge]][nongnu-elpa-link] [![MELPA badge][melpa-badge]][melpa-link] [![MELPA stable badge][melpa-stable-badge]][melpa-stable-link] [![Github Actions Status][github-actions-badge]][github-actions-link] [![Guide to Markdown Mode for Emacs][leanpub-badge]][leanpub-link]
 
   [nongnu-elpa-link]: https://elpa.nongnu.org/nongnu/markdown-mode.html
   [nongnu-elpa-badge]: https://elpa.nongnu.org/nongnu/markdown-mode.svg
   [melpa-link]: https://melpa.org/#/markdown-mode
   [melpa-stable-link]: https://stable.melpa.org/#/markdown-mode
   [melpa-badge]: https://melpa.org/packages/markdown-mode-badge.svg
   [melpa-stable-badge]: https://stable.melpa.org/packages/markdown-mode-badge.svg
   [github-actions-link]: https://github.com/jrblevin/markdown-mode/actions
   [github-actions-badge]: https://github.com/jrblevin/markdown-mode/workflows/CI/badge.svg
   [leanpub-link]: https://leanpub.com/markdown-mode
   [leanpub-badge]: https://img.shields.io/badge/leanpub-guide-orange.svg
 
 markdown-mode is a major mode for editing [Markdown][]-formatted
 text.  The latest stable version is markdown-mode 2.5, released on
 Feb 12, 2022.  See the [release notes][] for details.
 markdown-mode is free software, licensed under the GNU GPL,
 version 3 or later.
 
 ![Markdown Mode Screenshot](https://jblevins.org/projects/markdown-mode/screenshots/20170818-001.png)
 
 [Markdown]: http://daringfireball.net/projects/markdown/
 [release notes]: https://github.com/jrblevin/markdown-mode/releases/tag/v2.5
 
 ## Documentation
 
 <a href="https://leanpub.com/markdown-mode">
 <img src="https://jblevins.org/projects/markdown-mode/guide-v2.3.png" align="right" height="350" width="231">
 </a>
 
 The primary documentation for Markdown Mode is available below, and
 is generated from comments in the source code.  For a more in-depth
 treatment, the [_Guide to Markdown Mode for Emacs_][guide] covers
 Markdown syntax, advanced movement and editing in Emacs,
 extensions, configuration examples, tips and tricks, and a survey
 of other packages that work with Markdown Mode.  Finally, Emacs is
 also a self-documenting editor.  This means that the source code
 itself contains additional documentation: each function has its own
 docstring available via <kbd>C-h f</kbd> (`describe-function`), individual
 keybindings can be investigated with <kbd>C-h k</kbd> (`describe-key`), and
 a complete list of keybindings is available using <kbd>C-h m</kbd>
 (`describe-mode`).
 
  [guide]: https://leanpub.com/markdown-mode
 
 ## Installation
 
 _Note:_ To use all of the features of `markdown-mode`, you'll need
 to install the Emacs package itself and also have a local Markdown
 processor installed (e.g., Markdown.pl, MultiMarkdown, or Pandoc).
 The external processor is not required for editing, but will be
 used for rendering HTML for preview and export. After installing
 the Emacs package, be sure to configure `markdown-command` to point
 to the preferred Markdown executable on your system.  See the
 Customization section below for more details.
 
 The recommended way to install `markdown-mode` is to install the package
 from [MELPA Stable](https://stable.melpa.org/#/markdown-mode)
 using `package.el`. First, configure `package.el` and the MELPA Stable
 repository by adding the following to your `.emacs`, `init.el`,
 or equivalent startup file:
 
 ```lisp
 (require 'package)
 (add-to-list 'package-archives
              '("melpa-stable" . "https://stable.melpa.org/packages/"))
 (package-initialize)
 ```
 
 Then, after restarting Emacs or evaluating the above statements, issue
 the following command: <kbd>M-x package-install RET markdown-mode RET</kbd>.
 When installed this way, the major modes `markdown-mode` and `gfm-mode`
 will be autoloaded and `markdown-mode` will be used for file names
 ending in `.md`, `.markdown`, `.mkd`, `.mdown`, `.mkdn`, `.mdwn`.
 
 Alternatively, if you manage loading packages with [use-package][]
 then you can automatically install and configure `markdown-mode` by
 adding a declaration such as this one to your init file (as an
 example; adjust settings as desired):
 
 ```lisp
 (use-package markdown-mode
   :ensure t
   :mode ("README\\.md\\'" . gfm-mode)
   :init (setq markdown-command "multimarkdown"))
 ```
 
 [MELPA Stable]: http://stable.melpa.org/
 [use-package]: https://github.com/jwiegley/use-package
 
 **Direct Download**
 
 Alternatively you can manually download and install markdown-mode.
 First, download the [latest stable version][markdown-mode.el] and
 save the file where Emacs can find it (i.e., a directory in your
 `load-path`). You can then configure `markdown-mode` and `gfm-mode`
 to load automatically by adding the following to your init file:
 
 ```lisp
 (autoload 'markdown-mode "markdown-mode"
    "Major mode for editing Markdown files" t)
 (add-to-list 'auto-mode-alist
              '("\\.\\(?:md\\|markdown\\|mkd\\|mdown\\|mkdn\\|mdwn\\)\\'" . markdown-mode))
 
 (autoload 'gfm-mode "markdown-mode"
    "Major mode for editing GitHub Flavored Markdown files" t)
 (add-to-list 'auto-mode-alist '("README\\.md\\'" . gfm-mode))
 ```
 
 [markdown-mode.el]: https://raw.githubusercontent.com/jrblevin/markdown-mode/v2.5/markdown-mode.el
 
 **Development Version**
 
 To follow or contribute to markdown-mode development, you can
 browse or clone the Git repository
 [on GitHub](https://github.com/jrblevin/markdown-mode):
 
 ```
 git clone https://github.com/jrblevin/markdown-mode.git
 ```
 
 If you prefer to install and use the development version, which may
 become unstable at some times, you can either clone the Git
 repository as above or install markdown-mode from
 [MELPA](https://melpa.org/#/markdown-mode).
 
 If you clone the repository directly, then make sure that Emacs can
 find it by adding the following line to your startup file:
 
 ```lisp
 (add-to-list 'load-path "/path/to/markdown-mode/repository")
 ```
 
 **Packaged Installation**
 
 markdown-mode is also available in several package managers. You
 may want to confirm that the package you install contains the
 latest stable version first (and please notify the package
 maintainer if not).
 
    * Debian Linux: [elpa-markdown-mode][] and [emacs-goodies-el][]
    * Ubuntu Linux: [elpa-markdown-mode][elpa-ubuntu] and [emacs-goodies-el][emacs-goodies-el-ubuntu]
    * RedHat and Fedora Linux: [emacs-goodies][]
    * NetBSD: [textproc/markdown-mode][]
    * MacPorts: [markdown-mode.el][macports-package] ([pending][macports-ticket])
    * FreeBSD: [textproc/markdown-mode.el][freebsd-port]
 
  [elpa-markdown-mode]: https://packages.debian.org/sid/lisp/elpa-markdown-mode
  [elpa-ubuntu]: http://packages.ubuntu.com/search?keywords=elpa-markdown-mode
  [emacs-goodies-el]: http://packages.debian.org/emacs-goodies-el
  [emacs-goodies-el-ubuntu]: http://packages.ubuntu.com/search?keywords=emacs-goodies-el
  [emacs-goodies]: https://apps.fedoraproject.org/packages/emacs-goodies
  [textproc/markdown-mode]: http://pkgsrc.se/textproc/markdown-mode
  [macports-package]: https://trac.macports.org/browser/trunk/dports/editors/markdown-mode.el/Portfile
  [macports-ticket]: http://trac.macports.org/ticket/35716
  [freebsd-port]: http://svnweb.freebsd.org/ports/head/textproc/markdown-mode.el
 
 **Dependencies**
 
 To enable editing of code blocks in indirect buffers using <kbd>C-c '</kbd>,
 you will need to install the [`edit-indirect`][ei] package.
 
   [ei]: https://github.com/Fanael/edit-indirect/
 
 ## Usage
 
 Keybindings are grouped by prefixes based on their function.  For
 example, the commands for styling text are grouped under <kbd>C-c C-s</kbd>
 and toggle commands begin with <kbd>C-c C-x</kbd>.  The primary commands in
 each group will are described below.  You can obtain a list of all
 keybindings by pressing <kbd>C-c C-h</kbd>.  Movement and shifting commands
 tend to be associated with paired delimiters such as <kbd>M-{</kbd> and
 <kbd>M-}</kbd> or <kbd>C-c <</kbd> and <kbd>C-c ></kbd>.  Outline navigation keybindings the
 same as in `org-mode`.  Finally, commands for running Markdown or
 doing maintenance on an open file are grouped under the <kbd>C-c C-c</kbd>
 prefix.  The most commonly used commands are described below. You
 can obtain a list of all keybindings by pressing <kbd>C-c C-h</kbd>.
 
   * Links and Images: <kbd>C-c C-l</kbd> and <kbd>C-c C-i</kbd>
 
     <kbd>C-c C-l</kbd> (`markdown-insert-link`) is a general command for
     inserting new link markup or editing existing link markup. This
     is especially useful when markup or URL hiding is enabled, so
     that URLs can't easily be edited directly.  This command can be
     used to insert links of any form: either inline links,
     reference links, or plain URLs in angle brackets.  The URL or
     `[reference]` label, link text, and optional title are entered
     through a series of interactive prompts.  The type of link is
     determined by which values are provided:
 
     *   If both a URL and link text are given, insert an inline link:
         `[text](url)`.
     *   If both a `[reference]` label and link text are given, insert
         a reference link: `[text][reference]`.
     *   If only link text is given, insert an implicit reference link:
         `[text][]`.
     *   If only a URL is given, insert a plain URL link:
         `<url>`.
 
     Similarly, <kbd>C-c C-i</kbd> (`markdown-insert-image`) is a general
     command for inserting or editing image markup.  As with the link
     insertion command, through a series interactive prompts you can
     insert either an inline or reference image:
 
     *   If both a URL and alt text are given, insert an inline
         image: `![alt text](url)`.
     *   If both a `[reference]` label and alt text are given,
         insert a reference link: `![alt text][reference]`.
 
     If there is an existing link or image at the point, these
     command will edit the existing markup rather than inserting new
     markup.  Otherwise, if there is an active region, these commands
     use the region as either the default URL (if it seems to be a
     URL) or link text value otherwise.  In that case, the region
     will be deleted and replaced by the link.
 
     Note that these functions can be used to convert links and
     images from one type to another (inline, reference, or plain
     URL) by selectively adding or removing properties via the
     interactive prompts.
 
     If a reference label is given that is not yet defined, you
     will be prompted for the URL and optional title and the
     reference will be inserted according to the value of
     `markdown-reference-location`.  If a title is given, it will be
     added to the end of the reference definition and will be used
     to populate the title attribute when converted to HTML.  In addition, it is
     possible to have the `markdown-link-make-text-function` function, if
     non-nil, define the default link text before prompting the user for it.
 
     If `markdown-disable-tooltip-prompt` is non-nil, the user will not be
     prompted to add or modify a tooltip text.
 
     Images associated with image links may be displayed
     inline in the buffer by pressing <kbd>C-c C-x C-i</kbd>
     (`markdown-toggle-inline-images`).  This is a toggle command, so
     pressing this once again will remove inline images.
     By default, only local images are displayed.  However, remote
     images will also be downloaded and displayed if
     `markdown-display-remote-images` is non-nil.
 
     Large images may be scaled down to fit in the buffer using
     `markdown-max-image-size`, a cons cell of the form `(max-width
     . max-height)`.  Resizing requires Emacs to be built with
     ImageMagick support.
 
   * Text Styles: <kbd>C-c C-s</kbd>
 
     <kbd>C-c C-s i</kbd> inserts markup to make a region or word italic. If
     there is an active region, make the region italic.  If the point
     is at a non-italic word, make the word italic.  If the point is
     at an italic word or phrase, remove the italic markup.
     Otherwise, simply insert italic delimiters and place the point
     in between them.  Similarly, use <kbd>C-c C-s b</kbd> for bold, <kbd>C-c C-s c</kbd>
     for inline code, and <kbd>C-c C-s k</kbd> for inserting `<kbd>` tags.
 
     <kbd>C-c C-s q</kbd> inserts a blockquote using the active region, if
     any, or starts a new blockquote. <kbd>C-c C-s Q</kbd> is a variation
     which always operates on the region, regardless of whether it
     is active or not (i.e., when `transient-mark-mode` is off but
     the mark is set).  The appropriate amount of indentation, if
     any, is calculated automatically given the surrounding context,
     but may be adjusted later using the region indentation
     commands.
 
     <kbd>C-c C-s p</kbd> behaves similarly for inserting preformatted code
     blocks (with <kbd>C-c C-s P</kbd> being the region-only counterpart)
     and <kbd>C-c C-s C</kbd> inserts a GFM style backquote fenced code block.
 
   * Headings: <kbd>C-c C-s</kbd>
 
     To insert or replace headings, there are two options.  You can
     insert a specific level heading directly or you can have
     `markdown-mode` determine the level for you based on the previous
     heading.  As with the other markup commands, the heading
     insertion commands use the text in the active region, if any,
     as the heading text.  Otherwise, if the current line is not
     blank, they use the text on the current line.  Finally, the
     setext commands will prompt for heading text if there is no
     active region and the current line is blank.
 
     <kbd>C-c C-s h</kbd> inserts a heading with automatically chosen type and
     level (both determined by the previous heading).  <kbd>C-c C-s H</kbd>
     behaves similarly, but uses setext (underlined) headings when
     possible, still calculating the level automatically.
     In cases where the automatically-determined level is not what
     you intended, the level can be quickly promoted or demoted
     (as described below).  Alternatively, a <kbd>C-u</kbd> prefix can be
     given to insert a heading _promoted_ (lower number) by one
     level or a <kbd>C-u C-u</kbd> prefix can be given to insert a heading
     demoted (higher number) by one level.
 
     To insert a heading of a specific level and type, use <kbd>C-c C-s 1</kbd>
     through <kbd>C-c C-s 6</kbd> for atx (hash mark) headings and <kbd>C-c C-s !</kbd> or
     <kbd>C-c C-s @</kbd> for setext headings of level one or two, respectively.
     Note that <kbd>!</kbd> is <kbd>S-1</kbd> and <kbd>@</kbd> is <kbd>S-2</kbd>.
 
     If the point is at a heading, these commands will replace the
     existing markup in order to update the level and/or type of the
     heading.  To remove the markup of the heading at the point,
     press <kbd>C-c C-k</kbd> to kill the heading and press <kbd>C-y</kbd> to yank the
     heading text back into the buffer.
 
   * Horizontal Rules: <kbd>C-c C-s -</kbd>
 
     <kbd>C-c C-s -</kbd> inserts a horizontal rule.  By default, insert the
     first string in the list `markdown-hr-strings` (the most
     prominent rule).  With a <kbd>C-u</kbd> prefix, insert the last string.
     With a numeric prefix <kbd>N</kbd>, insert the string in position <kbd>N</kbd>
     (counting from 1).
 
   * Footnotes: <kbd>C-c C-s f</kbd>
 
     <kbd>C-c C-s f</kbd> inserts a footnote marker at the point, inserts a
     footnote definition below, and positions the point for
     inserting the footnote text.  Note that footnotes are an
     extension to Markdown and are not supported by all processors.
 
   * Wiki Links: <kbd>C-c C-s w</kbd>
 
     <kbd>C-c C-s w</kbd> inserts a wiki link of the form `[[WikiLink]]`.  If
     there is an active region, use the region as the link text.  If the
     point is at a word, use the word as the link text.  If there is
     no active region and the point is not at word, simply insert
     link markup.  Note that wiki links are an extension to Markdown
     and are not supported by all processors.
 
   * Markdown and Maintenance Commands: <kbd>C-c C-c</kbd>
 
     *Compile:* <kbd>C-c C-c m</kbd> will run Markdown on the current buffer
     and show the output in another buffer.  *Preview*: <kbd>C-c C-c p</kbd>
     runs Markdown on the current buffer and previews, stores the
     output in a temporary file, and displays the file in a browser.
     *Export:* <kbd>C-c C-c e</kbd> will run Markdown on the current buffer
     and save the result in the file `basename.html`, where
     `basename` is the name of the Markdown file with the extension
     removed.  *Export and View:* press <kbd>C-c C-c v</kbd> to export the
     file and view it in a browser.  *Open:* <kbd>C-c C-c o</kbd> will open
     the Markdown source file directly using `markdown-open-command`.
     *Live Export*: Press <kbd>C-c C-c l</kbd> to turn on
     `markdown-live-preview-mode` to view the exported output
     side-by-side with the source Markdown. **For all export commands,
     the output file will be overwritten without notice.**
     `markdown-live-preview-window-function` can be customized to open
     in a browser other than `eww`.  If you want to force the
     preview window to appear at the bottom or right, you can
     customize `markdown-split-window-direction`.
 
     To summarize:
 
       - <kbd>C-c C-c m</kbd>: `markdown-command` > `*markdown-output*` buffer.
       - <kbd>C-c C-c p</kbd>: `markdown-command` > temporary file > browser.
       - <kbd>C-c C-c e</kbd>: `markdown-command` > `basename.html`.
       - <kbd>C-c C-c v</kbd>: `markdown-command` > `basename.html` > browser.
       - <kbd>C-c C-c w</kbd>: `markdown-command` > kill ring.
       - <kbd>C-c C-c o</kbd>: `markdown-open-command`.
       - <kbd>C-c C-c l</kbd>: `markdown-live-preview-mode` > `*eww*` buffer.
 
     <kbd>C-c C-c c</kbd> will check for undefined references.  If there are
     any, a small buffer will open with a list of undefined
     references and the line numbers on which they appear.  In Emacs
     22 and greater, selecting a reference from this list and
     pressing <kbd>RET</kbd> will insert an empty reference definition at the
     end of the buffer.  Similarly, selecting the line number will
     jump to the corresponding line.
 
     <kbd>C-c C-c u</kbd> will check for unused references.  This will
     also open a small buffer if any are found, similar to undefined
     reference checking.  The buffer for unused references will contain
     `X` buttons that remove unused references when selected.
 
     <kbd>C-c C-c n</kbd> renumbers any ordered lists in the buffer that are
     out of sequence.
 
     <kbd>C-c C-c ]</kbd> completes all headings and normalizes all horizontal
     rules in the buffer.
 
   * Following Links: <kbd>C-c C-o</kbd>
 
     Press <kbd>C-c C-o</kbd> when the point is on an inline or reference
     link to open the URL in a browser.  When the point is at a
     wiki link, open it in another buffer (in the current window,
     or in the other window with the <kbd>C-u</kbd> prefix).  Use <kbd>M-p</kbd> and
     <kbd>M-n</kbd> to quickly jump to the previous or next link of any type.
 
   * Doing Things: <kbd>C-c C-d</kbd>
 
     Use <kbd>C-c C-d</kbd> to do something sensible with the object at the point:
 
       - Jumps between reference links and reference definitions.
         If more than one link uses the same reference label, a
         window will be shown containing clickable buttons for
         jumping to each link.  Pressing <kbd>TAB</kbd> or <kbd>S-TAB</kbd> cycles
         between buttons in this window.
       - Jumps between footnote markers and footnote text.
       - Toggles the completion status of GFM task list items
         (checkboxes).
       - Re-aligns table columns.
 
   * Promotion and Demotion: <kbd>C-c C--</kbd> and <kbd>C-c C-=</kbd>
 
     Headings, horizontal rules, and list items can be promoted and
     demoted, as well as bold and italic text.  For headings,
     "promotion" means *decreasing* the level (i.e., moving from
     `<h2>` to `<h1>`) while "demotion" means *increasing* the
     level.  For horizontal rules, promotion and demotion means
     moving backward or forward through the list of rule strings in
     `markdown-hr-strings`.  For bold and italic text, promotion and
     demotion means changing the markup from underscores to asterisks.
     Press <kbd>C-c C--</kbd> or <kbd>C-c LEFT</kbd> to promote the element at the point
     if possible.
 
     To remember these commands, note that <kbd>-</kbd> is for decreasing the
     level (promoting), and <kbd>=</kbd> (on the same key as <kbd>+</kbd>) is for
     increasing the level (demoting).  Similarly, the left and right
     arrow keys indicate the direction that the atx heading markup
     is moving in when promoting or demoting.
 
   * Completion: <kbd>C-c C-]</kbd>
 
     Complete markup is in normalized form, which means, for
     example, that the underline portion of a setext header is the
     same length as the heading text, or that the number of leading
     and trailing hash marks of an atx header are equal and that
     there is no extra whitespace in the header text.  <kbd>C-c C-]</kbd>
     completes the markup at the point, if it is determined to be
     incomplete.
 
   * Editing Lists: <kbd>M-RET</kbd>, <kbd>C-c UP</kbd>, <kbd>C-c DOWN</kbd>, <kbd>C-c LEFT</kbd>, and <kbd>C-c RIGHT</kbd>
 
     New list items can be inserted with <kbd>M-RET</kbd> or <kbd>C-c C-j</kbd>.  This
     command determines the appropriate marker (one of the possible
     unordered list markers or the next number in sequence for an
     ordered list) and indentation level by examining nearby list
     items.  If there is no list before or after the point, start a
     new list.  As with heading insertion, you may prefix this
     command by <kbd>C-u</kbd> to decrease the indentation by one level.
     Prefix this command by <kbd>C-u C-u</kbd> to increase the indentation by
     one level.
 
     Existing list items (and their nested sub-items) can be moved
     up or down with <kbd>C-c UP</kbd> or <kbd>C-c DOWN</kbd> and indented or
     outdented with <kbd>C-c RIGHT</kbd> or <kbd>C-c LEFT</kbd>.
 
   * Editing Subtrees: <kbd>C-c UP</kbd>, <kbd>C-c DOWN</kbd>, <kbd>C-c LEFT</kbd>, and <kbd>C-c RIGHT</kbd>
 
     Entire subtrees of ATX headings can be promoted and demoted
     with <kbd>C-c LEFT</kbd> and <kbd>C-c RIGHT</kbd>, which are the same keybindings
     used for promotion and demotion of list items.   If the point is in
     a list item, the operate on the list item.  Otherwise, they operate
     on the current heading subtree.  Similarly, subtrees can be
     moved up and down with <kbd>C-c UP</kbd> and <kbd>C-c DOWN</kbd>.
 
     These commands currently do not work properly if there are
     Setext headings in the affected region.
 
     Please note the following "boundary" behavior for promotion and
     demotion.  Any level-six headings will not be demoted further
     (i.e., they remain at level six, since Markdown and HTML define
     only six levels) and any level-one headings will promoted away
     entirely (i.e., heading markup will be removed, since a
     level-zero heading is not defined).
 
   * Shifting the Region: <kbd>C-c <</kbd> and <kbd>C-c ></kbd>
 
     Text in the region can be indented or outdented as a group using
     <kbd>C-c ></kbd> to indent to the next indentation point (calculated in
     the current context), and <kbd>C-c <</kbd> to outdent to the previous
     indentation point.  These keybindings are the same as those for
     similar commands in `python-mode`.
 
   * Killing Elements: <kbd>C-c C-k</kbd>
 
     Press <kbd>C-c C-k</kbd> to kill the thing at point and add important
     text, without markup, to the kill ring.  Possible things to
     kill include (roughly in order of precedece): inline code,
     headings, horizontal rules, links (add link text to kill ring),
     images (add alt text to kill ring), angle URIs, email
     addresses, bold, italics, reference definitions (add URI to
     kill ring), footnote markers and text (kill both marker and
     text, add text to kill ring), and list items.
 
   * Outline Navigation: <kbd>C-c C-n</kbd>, <kbd>C-c C-p</kbd>, <kbd>C-c C-f</kbd>, <kbd>C-c C-b</kbd>, and <kbd>C-c C-u</kbd>
 
     These keys are used for hierarchical navigation in lists and
     headings.  When the point is in a list, they move between list
     items.  Otherwise, they move between headings.  Use <kbd>C-c C-n</kbd> and
     <kbd>C-c C-p</kbd> to move between the next and previous visible
     headings or list items of any level.  Similarly, <kbd>C-c C-f</kbd> and
     <kbd>C-c C-b</kbd> move to the next and previous visible headings or
     list items at the same level as the one at the point.  Finally,
     <kbd>C-c C-u</kbd> will move up to the parent heading or list item.
 
   * Movement by Markdown paragraph: <kbd>M-{</kbd>, <kbd>M-}</kbd>, and <kbd>M-h</kbd>
 
     Paragraphs in `markdown-mode` are regular paragraphs,
     paragraphs inside blockquotes, individual list items, headings,
     etc.  These keys are usually bound to `forward-paragraph` and
     `backward-paragraph`, but the built-in Emacs functions are
     based on simple regular expressions that fail in Markdown
     files.  Instead, they are bound to `markdown-forward-paragraph`
     and `markdown-backward-paragraph`.  To mark a paragraph,
     you can use <kbd>M-h</kbd> (`markdown-mark-paragraph`).
 
   * Movement by Markdown block: <kbd>C-M-{</kbd>, <kbd>C-M-}</kbd>, and <kbd>C-c M-h</kbd>
 
     Markdown blocks are regular paragraphs in many cases, but
     contain many paragraphs in other cases: blocks are considered
     to be entire lists, entire code blocks, and entire blockquotes.
     To move backward one block use <kbd>C-M-{</kbd>
     (`markdown-beginning-block`) and to move forward use <kbd>C-M-}</kbd>
     (`markdown-end-of-block`).  To mark a block, use <kbd>C-c M-h</kbd>
     (`markdown-mark-block`).
 
   * Movement by Defuns: <kbd>C-M-a</kbd>, <kbd>C-M-e</kbd>, and <kbd>C-M-h</kbd>
 
     The usual Emacs commands can be used to move by defuns
     (top-level major definitions).  In markdown-mode, a defun is a
     section.  As usual, <kbd>C-M-a</kbd> will move the point to the
     beginning of the current or preceding defun, <kbd>C-M-e</kbd> will move
     to the end of the current or following defun, and <kbd>C-M-h</kbd> will
     put the region around the entire defun.
 
   * Table Editing:
 
     Markdown Mode includes support for editing tables, which
     have the following basic format:
 
         | Right | Left | Center | Default |
         |------:|:-----|:------:|---------|
         |    12 | 12   | 12     | 12      |
         |   123 | 123  | 123    | 123     |
         |     1 | 1    | 1      | 1       |
 
     The first line contains column headers. The second line
     contains a separator line between the headers and the content.
     Each following line is a row in the table.  Columns are always
     separated by the pipe character.  The colons indicate column
     alignment.
 
     A table is re-aligned automatically each time you press <kbd>TAB</kbd>
     or <kbd>RET</kbd> inside the table.  <kbd>TAB</kbd> also moves to the next
     field (<kbd>RET</kbd> to the next row) and creates new table rows at
     the end of the table or before horizontal separator lines.  The
     indentation of the table is set by the first line.  Column
     centering inside Emacs is not supported.
 
     Beginning pipe characters are required for proper detection of
     table borders inside Emacs.  Any line starting with `|-` or `|:`
     is considered as a horizontal separator line and will be
     expanded on the next re-align to span the whole table width.  No
     padding is allowed between the beginning pipe character and
     header separator symbol.  So, to create the above table, you
     would only type
 
         |Right|Left|Center|Default|
         |-
 
     and then press <kbd>TAB</kbd> to align the table and start filling in
     cells.
 
     Then you can jump with <kbd>TAB</kbd> from one cell to the next or with
     <kbd>S-TAB</kbd> to the previous one.  <kbd>RET</kbd> will jump to the to the
     next cell in the same column, and create a new row if there is
     no such cell or if the next row is beyond a separator line.
 
     You can also convert selected region to a table. Basic editing
     capabilities include inserting, deleting, and moving of columns
     and rows, and table re-alignment, sorting, transposition:
 
       - <kbd>C-c UP</kbd> or <kbd>C-c DOWN</kbd> - Move the current row up or down.
       - <kbd>C-c LEFT</kbd> or <kbd>C-c RIGHT</kbd> - Move the current column left or right.
       - <kbd>C-c S-UP</kbd> - Kill the current row.
       - <kbd>C-c S-DOWN</kbd> - Insert a row above the current row. With a
         prefix argument, row line is created below the current one.
       - <kbd>C-c S-LEFT</kbd> - Kill the current column.
       - <kbd>C-c S-RIGHT</kbd> - Insert a new column to the left of the current one.
       - <kbd>C-c C-d</kbd> - Re-align the current table (`markdown-do`).
       - <kbd>C-c C-c ^</kbd> - Sort the rows of a table by a specified column.
         This command prompts you for the column number and a sort
         method (alphabetical or numerical, optionally in reverse).
       - <kbd>C-c C-c |</kbd> - Convert the region to a table.  This function
         attempts to recognize comma, tab, and space separated data
         and then splits the data into cells accordingly.
       - <kbd>C-c C-c t</kbd> - Transpose table at point.
 
     The table editing functions try to handle markup hiding
     correctly when calculating column widths, however, columns
     containing hidden markup may not always be aligned properly.
 
     <kbd>C-c C-s t</kbd> (`markdown-insert-table`) is a general command for inserting new table.
     The command prompts for table size and column alignment and inserts an empty pipe table at point.
 
   * Viewing Modes:
 
     Read-only viewing modes, `markdown-view-mode` and `gfm-view-mode`
     are provided for viewing Markdown content.  These modes provide
     simplified keybindings for navigating the buffer.  Many of these
     are like `help-mode` and `view-mode`, such as <kbd>SPC</kbd>,
     <kbd>DEL</kbd>, <kbd><</kbd>, and <kbd>></kbd> for scrolling,
     <kbd>q</kbd> for quitting, and <kbd>?</kbd> or <kbd>h</kbd> for
     help.  Other keys are provided that mirror the outline navigation
     commands when editing: <kbd>n</kbd>, <kbd>p</kbd>, <kbd>f</kbd>,
     <kbd>b</kbd>, and <kbd>u</kbd>.  Both of these modes enable markup
     hiding by default, but this can be customized by setting
     `markdown-hide-markup-in-view-modes`.
 
   * Miscellaneous Commands:
 
     When the [`edit-indirect`][ei] package is installed, <kbd>C-c '</kbd>
     (`markdown-edit-code-block`) can be used to edit a code block
     in an indirect buffer in the native major mode. Press <kbd>C-c C-c</kbd>
     to commit changes and return or <kbd>C-c C-k</kbd> to cancel.  You can
     also give a prefix argument to the insertion command, as in
     <kbd>C-u C-c C-s C</kbd>, to edit the code block in an indirect buffer
     upon insertion.
 
 As noted, many of the commands above behave differently depending
 on whether Transient Mark mode is enabled or not.  When it makes
 sense, if Transient Mark mode is on and the region is active, the
 command applies to the text in the region (e.g., <kbd>C-c C-s b</kbd> makes the
 region bold).  For users who prefer to work outside of Transient
 Mark mode, since Emacs 22 it can be enabled temporarily by pressing
 <kbd>C-SPC C-SPC</kbd>.  When this is not the case, many commands then
 proceed to look work with the word or line at the point.
 
 When applicable, commands that specifically act on the region even
 outside of Transient Mark mode have the same keybinding as their
 standard counterpart, but the letter is uppercase.  For example,
 `markdown-insert-blockquote` is bound to <kbd>C-c C-s q</kbd> and only acts on
 the region in Transient Mark mode while `markdown-blockquote-region`
 is bound to <kbd>C-c C-s Q</kbd> and always applies to the region (when nonempty).
 
 Note that these region-specific functions are useful in many
 cases where it may not be obvious.  For example, yanking text from
 the kill ring sets the mark at the beginning of the yanked text
 and moves the point to the end.  Therefore, the (inactive) region
 contains the yanked text.  So, <kbd>C-y</kbd> followed by <kbd>C-c C-s Q</kbd> will
 yank text and turn it into a blockquote.
 
 markdown-mode attempts to be flexible in how it handles
 indentation.  When you press <kbd>TAB</kbd> repeatedly, the point will cycle
 through several possible indentation levels corresponding to things
 you might have in mind when you press <kbd>RET</kbd> at the end of a line or
 <kbd>TAB</kbd>.  For example, you may want to start a new list item,
 continue a list item with hanging indentation, indent for a nested
 pre block, and so on.  Outdenting is handled similarly when backspace
 is pressed at the beginning of the non-whitespace portion of a line.
 
 markdown-mode supports outline-minor-mode as well as org-mode-style
 visibility cycling for atx- or hash-style headings.  There are two
 types of visibility cycling: Pressing <kbd>S-TAB</kbd> cycles globally between
 the table of contents view (headings only), outline view (top-level
 headings only), and the full document view.  Pressing <kbd>TAB</kbd> while the
 point is at a heading will cycle through levels of visibility for the
 subtree: completely folded, visible children, and fully visible.
 Note that mixing hash and underline style headings will give undesired
 results.
 
 ## Customization
 
 Although no configuration is *necessary* there are a few things
 that can be customized.  The <kbd>M-x customize-mode</kbd> command
 provides an interface to all of the possible customizations:
 
   * `markdown-command` - the command used to run Markdown (default:
     `markdown`).  This variable may be customized to pass
     command-line options to your Markdown processor of choice. We recommend
     you to use list of strings if you want to set command line options like.
     `'("pandoc" "--from=markdown" "--to=html5")`.  It can also be a
     function; in this case `markdown` will call it with three
     arguments: the beginning and end of the region to process, and
     a buffer to write the output to.
 
   * `markdown-command-needs-filename` - set to `t` if
     `markdown-command` does not accept standard input (default:
     `nil`).  When `nil`, `markdown-mode` will pass the Markdown
     content to `markdown-command` using standard input (`stdin`).
     When set to `t`, `markdown-mode` will pass the name of the file
     as the final command-line argument to `markdown-command`.  Note
     that in the latter case, you will only be able to run
     `markdown-command` from buffers which are visiting a file.  If
     `markdown-command` is a function, `markdown-command-needs-filename`
     is ignored.
 
   * `markdown-open-command` - the command used for calling a standalone
     Markdown previewer which is capable of opening Markdown source files
     directly (default: `nil`).  This command will be called
     with a single argument, the filename of the current buffer.
     A representative program is the Mac app [Marked 2][], a
     live-updating Markdown previewer which can be [called from a
     simple shell script](https://jblevins.org/log/marked-2-command).
     This variable can also be a function; in this case `markdown-open`
     will call it without arguments to preview the current buffer.
 
   * `markdown-open-image-command` - the command used for opening image
     link (default: `nil`) via `markdown-follow-*` commands. This variable
     can also be a function, in this case it is called with a single argument,
     image-link. If this value is `nil`, `markdown-mode` opens image links
     by `find-file`.
 
   * `markdown-hr-strings` - list of strings to use when inserting
     horizontal rules.  Different strings will not be distinguished
     when converted to HTML--they will all be converted to
     `<hr/>`--but they may add visual distinction and style to plain
     text documents.  To maintain some notion of promotion and
     demotion, keep these sorted from largest to smallest.
 
   * `markdown-bold-underscore` - set to a non-nil value to use two
     underscores when inserting bold text instead of two asterisks
     (default: `nil`).
 
   * `markdown-italic-underscore` - set to a non-nil value to use
     underscores when inserting italic text instead of asterisks
     (default: `nil`).
 
   * `markdown-asymmetric-header` - set to a non-nil value to use
     asymmetric header styling, placing header characters only on
     the left of headers (default: `nil`).
 
   * `markdown-header-scaling` - set to a non-nil value to use
     a variable-pitch font for headings where the size corresponds
     to the level of the heading (default: `nil`).
 
   * `markdown-header-scaling-values` - list of scaling values,
     relative to baseline, for headers of levels one through six,
     used when `markdown-header-scaling` is non-nil
     (default: `(2.0 1.7 1.4 1.1 1.0 1.0)`).
 
   * `markdown-marginalize-headers` - put opening atx header markup
     in the left margin when non-nil (default: `nil`).
 
   * `markdown-marginalize-headers-margin-width` - width of margin
     used for marginalized headers (default: 6).
 
   * `markdown-list-indent-width` - depth of indentation for lists
     when inserting, promoting, and demoting list items (default: 4).
 
   * `markdown-indent-function` - the function to use for automatic
     indentation (default: `markdown-indent-line`).
 
   * `markdown-indent-on-enter` - Set to a non-nil value to
     automatically indent new lines when <kbd>RET</kbd> is pressed.
     Set to `indent-and-new-item` to additionally continue lists
     when <kbd>RET</kbd> is pressed (default: `t`).
 
   * `markdown-enable-wiki-links` - syntax highlighting for wiki
     links (default: `nil`).  Set this to a non-nil value to turn on
     wiki link support by default.  Wiki link support can be toggled
     later using the function `markdown-toggle-wiki-links`."
 
   * `markdown-wiki-link-alias-first` - set to a non-nil value to
     treat aliased wiki links like `[[link text|PageName]]`
     (default: `t`).  When set to nil, they will be treated as
     `[[PageName|link text]]`.
 
   * `markdown-uri-types` - a list of protocol schemes (e.g., "http")
     for URIs that `markdown-mode` should highlight.
 
   * `markdown-enable-math` - font lock for inline and display LaTeX
     math expressions (default: `nil`).  Set this to `t` to turn on
     math support by default.  Math support can be toggled
     interactively later using <kbd>C-c C-x C-e</kbd>
     (`markdown-toggle-math`).
 
   * `markdown-enable-html` - font lock for HTML tags and attributes
     (default: `t`).
 
   * `markdown-css-paths` - CSS files to link to in XHTML output
     (default: `nil`). These can be either local files (relative or
     absolute) or URLs.
 
   * `markdown-content-type` - used to set to the `http-equiv`
     attribute to be included in the XHTML `<head>` block (default:
     `"text/html"`).  Set to an alternate value `application/xhtml+xml`
     if needed, or set to an empty string to remove the attribute.  See
     also: `markdown-coding-system`.
 
   * `markdown-coding-system` - used for specifying the character
     set identifier in the `http-equiv` attribute when included
     (default: `nil`).  See `markdown-content-type`, which must
     be set for this variable to have any effect.  When set to `nil`,
     `buffer-file-coding-system` will be used to automatically
     determine the coding system string (falling back to
     `utf-8` when unavailable).  Common settings are `iso-8859-1`
     and `iso-latin-1`.
 
   * `markdown-xhtml-header-content` - additional content to include
     in the XHTML `<head>` block (default: `""`).
 
   * `markdown-xhtml-body-preamble` - additional content to include in
     the XHTML <body> block, before the output (default: `""`).  This
     is useful for enclosing additional elements around the Markdown
     output.
 
   * `markdown-xhtml-body-epilogue` - additional content to include in
     the XHTML <body> block, after the output (default: `""`).  This is
     useful for enclosing additional elements around the Markdown
     output.
 
   * `markdown-xhtml-standalone-regexp` - a regular expression which
     `markdown-mode` uses to determine whether the output of
     `markdown-command` is a standalone XHTML document or an XHTML
     fragment (default: `"^\\(<\\?xml\\|<!DOCTYPE\\|<html\\)"`).  If
     this regular expression not matched in the first five lines of
     output, `markdown-mode` assumes the output is a fragment and
     adds a header and footer.
 
   * `markdown-link-space-sub-char` - a character to replace spaces
     when mapping wiki links to filenames (default: `"_"`).
     For example, use an underscore for compatibility with the
     Python Markdown WikiLinks extension.  In `gfm-mode`, this is
     set to `"-"` to conform with GitHub wiki links.
 
   * `markdown-reference-location` - where to insert reference
     definitions (default: `header`).  The possible locations are
     the end of the document (`end`), after the current block
     (`immediately`), the end of the current subtree (`subtree`),
     or before the next header (`header`).
 
   * `markdown-footnote-location` - where to insert footnote text
     (default: `end`).  The set of location options is the same as
     for `markdown-reference-location`.
 
   * `markdown-nested-imenu-heading-index` - Use nested imenu
     heading instead of a flat index (default: `t`).  A nested
     index may provide more natural browsing from the menu, but a
     flat list may allow for faster keyboard navigation via tab
     completion.
 
   * `markdown-add-footnotes-to-imenu` - Add footnote definitions to
     the end of the imenu index (default: `t`).
 
   * `comment-auto-fill-only-comments` - variable is made
     buffer-local and set to `nil` by default.  In programming
     language modes, when this variable is non-nil, only comments
     will be filled by auto-fill-mode.  However, comments in
     Markdown documents are rare and the most users probably intend
     for the actual content of the document to be filled.  Making
     this variable buffer-local allows `markdown-mode` to override
     the default behavior induced when the global variable is non-nil.
 
   * `markdown-gfm-additional-languages`, - additional languages to
     make available, aside from those predefined in
     `markdown-gfm-recognized-languages`, when inserting GFM code
     blocks (default: `nil`). Language strings must have be trimmed
     of whitespace and not contain any curly braces. They may be of
     arbitrary capitalization, though.
 
   * `markdown-gfm-use-electric-backquote` - use
     `markdown-electric-backquote` for interactive insertion of GFM
     code blocks when backquote is pressed three times (default: `t`).
 
   * `markdown-make-gfm-checkboxes-buttons` - Whether GitHub
     Flavored Markdown style task lists (checkboxes) should be
     turned into buttons that can be toggled with mouse-1 or RET. If
     non-nil (default), then buttons are enabled.  This works in
     `markdown-mode` as well as `gfm-mode`.
 
   * `markdown-hide-urls` - Determines whether URL and reference
     labels are hidden for inline and reference links (default: `nil`).
     When non-nil, inline links will appear in the buffer as
     `[link](∞)` instead of
     `[link](http://perhaps.a/very/long/url/)`.  To change the
     placeholder (composition) character used, set the variable
     `markdown-url-compose-char`.  URL hiding can be toggled
     interactively using <kbd>C-c C-x C-l</kbd> (`markdown-toggle-url-hiding`)
     or from the Markdown | Links & Images menu.
 
   * `markdown-hide-markup` - Determines whether all possible markup
     is hidden or otherwise beautified (default: `nil`).   The actual
     buffer text remains unchanged, but the display will be altered.
     Brackets and URLs for links will be hidden, asterisks and
     underscores for italic and bold text will be hidden, text
     bullets for unordered lists will be replaced by Unicode
     bullets, and so on.  Since this includes URLs and reference
     labels, when non-nil this setting supersedes `markdown-hide-urls`.
     Markup hiding can be toggled using <kbd>C-c C-x C-m</kbd>
     (`markdown-toggle-markup-hiding`) or from the Markdown | Show &
     Hide menu.
 
     Unicode bullets are used to replace ASCII list item markers.
     The list of characters used, in order of list level, can be
     specified by setting the variable `markdown-list-item-bullets`.
     The placeholder characters used to replace other markup can
     be changed by customizing the corresponding variables:
     `markdown-blockquote-display-char`,
     `markdown-hr-display-char`, and
     `markdown-definition-display-char`.
 
   * `markdown-fontify-code-blocks-natively` - Whether to fontify
     code in code blocks using the native major mode.  This only
     works for fenced code blocks where the language is specified
     where we can automatically determine the appropriate mode to
     use.  The language to mode mapping may be customized by setting
     the variable `markdown-code-lang-modes`.  This can be toggled
     interactively by pressing <kbd>C-c C-x C-f</kbd>
     (`markdown-toggle-fontify-code-blocks-natively`).
 
   * `markdown-gfm-uppercase-checkbox` - When non-nil, complete GFM
     task list items with `[X]` instead of `[x]` (default: `nil`).
     This is useful for compatibility with `org-mode`, which doesn't
     recognize the lowercase variant.
 
   * `markdown-translate-filename-function` - A function to be used to
     translate filenames in links.
 
   * `markdown-unordered-list-item-prefix` - When non-nil,
     `markdown-insert-list-item` inserts enumerated numbers for
     ordered list marker. While nil, it always inserts `1.`.
 
   * `markdown-enable-highlighting-syntax` - font lock for highlighting
      syntax like Obsidian, Quilt(default: `nil`).
 
 Additionally, the faces used for syntax highlighting can be modified to
 your liking by issuing <kbd>M-x customize-group RET markdown-faces</kbd>
 or by using the "Markdown Faces" link at the bottom of the mode
 customization screen.
 
 [Marked 2]: https://itunes.apple.com/us/app/marked-2/id890031187?mt=12&uo=4&at=11l5Vs&ct=mm
 
 ## Extensions
 
 Besides supporting the basic Markdown syntax, Markdown Mode also
 includes syntax highlighting for `[[Wiki Links]]`.  This can be
 enabled by setting `markdown-enable-wiki-links` to a non-nil value.
 Wiki links may be followed by pressing <kbd>C-c C-o</kbd> when the point
 is at a wiki link.  Use <kbd>M-p</kbd> and <kbd>M-n</kbd> to quickly jump to the
 previous and next links (including links of other types).
 Aliased or piped wiki links of the form `[[link text|PageName]]`
 are also supported.  Since some wikis reverse these components, set
 `markdown-wiki-link-alias-first` to nil to treat them as
 `[[PageName|link text]]`.  If `markdown-wiki-link-fontify-missing`
 is also non-nil, Markdown Mode will highlight wiki links with
 missing target file in a different color.  By default, Markdown
 Mode only searches for target files in the current directory.
 You can control search type by setting `markdown-wiki-link-search-type`.
 This value type is a symbol list. Possible values are
 
 - `sub-directories` : search in sub directories
 - `parent-directories` : search in parent directories
 - `project` : search under project root
 
 [SmartyPants][] support is possible by customizing `markdown-command`.
 If you install `SmartyPants.pl` at, say, `/usr/local/bin/smartypants`,
 then you can set `markdown-command` to `"markdown | smartypants"`.
 You can do this either by using <kbd>M-x customize-group markdown</kbd>
 or by placing the following in your `.emacs` file:
 
 ```lisp
 (setq markdown-command "markdown | smartypants")
 ```
 
 [SmartyPants]: http://daringfireball.net/projects/smartypants/
 
 Syntax highlighting for mathematical expressions written
 in LaTeX (only expressions denoted by `$..$`, `$$..$$`, or `\[..\]`)
 can be enabled by setting `markdown-enable-math` to a non-nil value,
 either via customize or by placing `(setq markdown-enable-math t)`
 in `.emacs`, and then restarting Emacs or calling
 `markdown-reload-extensions`.
 
 ## GitHub Flavored Markdown (GFM)
 
 A [GitHub Flavored Markdown][GFM] mode, `gfm-mode`, is also
 available.  The GitHub implementation differs slightly from
 standard Markdown in that it supports things like different
 behavior for underscores inside of words, automatic linking of
 URLs, strikethrough text, and fenced code blocks with an optional
 language keyword.
 
 The GFM-specific features above apply to `README.md` files, wiki
 pages, and other Markdown-formatted files in repositories on
 GitHub.  GitHub also enables [additional features][GFM comments] for
 writing on the site (for issues, pull requests, messages, etc.)
 that are further extensions of GFM.  These features include task
 lists (checkboxes), newlines corresponding to hard line breaks,
 auto-linked references to issues and commits, wiki links, and so
 on.  To make matters more confusing, although task lists are not
 part of [GFM proper][GFM], [since 2014][] they are rendered (in a
 read-only fashion) in all Markdown documents in repositories on the
 site.  These additional extensions are supported to varying degrees
 by `markdown-mode` and `gfm-mode` as described below.
 
 * **URL autolinking:** Both `markdown-mode` and `gfm-mode` support
   highlighting of URLs without angle brackets.
 
 * **Multiple underscores in words:** You must enable `gfm-mode` to
   toggle support for underscores inside of words. In this mode
   variable names such as `a_test_variable` will not trigger
   emphasis (italics).
 
 * **Fenced code blocks:** Code blocks quoted with backquotes, with
   optional programming language keywords, are highlighted in
   both `markdown-mode` and `gfm-mode`.  They can be inserted with
   <kbd>C-c C-s C</kbd>.  If there is an active region, the text in the
   region will be placed inside the code block.  You will be
   prompted for the name of the language, but may press enter to
   continue without naming a language.
 
   In addition, in `gfm-mode`, GFM code blocks can be inserted via the
   option `markdown-gfm-use-electric-backquote`. If the option
   `markdown-code-block-braces` is set to `t`, code blocks inserted with
   <kbd>C-c C-s C</kbd> or electric backquotes will include braces ("{}")
   around the language attributes.
 
 * **Strikethrough:** Strikethrough text is supported in both
   `markdown-mode` and `gfm-mode`.  It can be inserted (and toggled)
   using <kbd>C-c C-s s</kbd>.
 
 * **Task lists:** GFM task lists will be rendered as checkboxes
   (Emacs buttons) in both `markdown-mode` and `gfm-mode` when
   `markdown-make-gfm-checkboxes-buttons` is set to a non-nil value
   (and it is set to t by default).  These checkboxes can be
   toggled by clicking `mouse-1`, pressing <kbd>RET</kbd> over the button,
   or by pressing <kbd>C-c C-d</kbd> (`markdown-do`) with the point anywhere
   in the task list item.  A normal list item can be turned to a
   check list item by the same command, or more specifically
   <kbd>C-c C-s [</kbd> (`markdown-insert-gfm-checkbox`).
 
 * **Wiki links:** Generic wiki links are supported in
   `markdown-mode`, but in `gfm-mode` specifically they will be
   treated as they are on GitHub: spaces will be replaced by hyphens
   in filenames and the first letter of the filename will be
   capitalized.  For example, `[[wiki link]]` will map to a file
   named `Wiki-link` with the same extension as the current file.
   If a file with this name does not exist in the current directory,
   the first match in a subdirectory, if any, will be used instead.
 
 * **Newlines:** Neither `markdown-mode` nor `gfm-mode` do anything
   specifically with respect to newline behavior.  If you use
   `gfm-mode` mostly to write text for comments or issues on the
   GitHub site--where newlines are significant and correspond to
   hard line breaks--then you may want to enable `visual-line-mode`
   for line wrapping in buffers.  You can do this with a
   `gfm-mode-hook` as follows:
 
     ```lisp
     ;; Use visual-line-mode in gfm-mode
     (defun my-gfm-mode-hook ()
       (visual-line-mode 1))
     (add-hook 'gfm-mode-hook 'my-gfm-mode-hook)
     ```
 
 * **Preview:** GFM-specific preview can be powered by setting
   `markdown-command` to use [Docter][].  This may also be
   configured to work with [Marked 2][] for `markdown-open-command`.
 
 [GFM]: http://github.github.com/github-flavored-markdown/
 [GFM comments]: https://help.github.com/articles/writing-on-github/
 [since 2014]: https://github.com/blog/1825-task-lists-in-all-markdown-documents
 [Docter]: https://github.com/alampros/Docter
 
 ## Acknowledgments
 
 markdown-mode has benefited greatly from the efforts of the many
 volunteers who have sent patches, test cases, bug reports,
 suggestions, helped with packaging, etc.  Thank you for your
 contributions!  See the [contributors graph][contrib] for details.
 
  [contrib]: https://github.com/jrblevin/markdown-mode/graphs/contributors
 
 ## Bugs
 
 markdown-mode is developed and tested primarily for compatibility
 with GNU Emacs 25.1 and later.  If you find any bugs in
 markdown-mode, please construct a test case or a patch and open a
 ticket on the [GitHub issue tracker][issues].  See the
 contributing guidelines in `CONTRIBUTING.md` for details on
 creating pull requests.
 
  [issues]: https://github.com/jrblevin/markdown-mode/issues
 
 ## History
 
 markdown-mode was written and is maintained by Jason Blevins.  The
 first version was released on May 24, 2007.
 
   * 2007-05-24: [Version 1.1][]
   * 2007-05-25: [Version 1.2][]
   * 2007-06-05: [Version 1.3][]
   * 2007-06-29: [Version 1.4][]
   * 2007-10-11: [Version 1.5][]
   * 2008-06-04: [Version 1.6][]
   * 2009-10-01: [Version 1.7][]
   * 2011-08-12: [Version 1.8][]
   * 2011-08-15: [Version 1.8.1][]
   * 2013-01-25: [Version 1.9][]
   * 2013-03-24: [Version 2.0][]
   * 2016-01-09: [Version 2.1][]
   * 2017-05-26: [Version 2.2][]
   * 2017-08-31: [Version 2.3][]
   * 2020-05-30: [Version 2.4][]
   * 2022-02-12: [Version 2.5][]
 
 [Version 1.1]: https://jblevins.org/projects/markdown-mode/rev-1-1
 [Version 1.2]: https://jblevins.org/projects/markdown-mode/rev-1-2
 [Version 1.3]: https://jblevins.org/projects/markdown-mode/rev-1-3
 [Version 1.4]: https://jblevins.org/projects/markdown-mode/rev-1-4
 [Version 1.5]: https://jblevins.org/projects/markdown-mode/rev-1-5
 [Version 1.6]: https://jblevins.org/projects/markdown-mode/rev-1-6
 [Version 1.7]: https://jblevins.org/projects/markdown-mode/rev-1-7
 [Version 1.8]: https://jblevins.org/projects/markdown-mode/rev-1-8
 [Version 1.8.1]: https://jblevins.org/projects/markdown-mode/rev-1-8-1
 [Version 1.9]: https://jblevins.org/projects/markdown-mode/rev-1-9
 [Version 2.0]: https://jblevins.org/projects/markdown-mode/rev-2-0
 [Version 2.1]: https://jblevins.org/projects/markdown-mode/rev-2-1
 [Version 2.2]: https://jblevins.org/projects/markdown-mode/rev-2-2
 [Version 2.3]: https://jblevins.org/projects/markdown-mode/rev-2-3
 [Version 2.4]: https://github.com/jrblevin/markdown-mode/releases/tag/v2.4
 [Version 2.5]: https://github.com/jrblevin/markdown-mode/releases/tag/v2.5