Log Message:
Update textproc/markdown-mode to 2.1

New Features

  General

    - Add automatically updating live preview functionality (C-c C-c l)
      via the native eww browser.
    - Use autoload to enable markdown-mode in auto-mode-alist for files
      with .text, .markdown, and .md extensions.
    - Use Travis CI for automated build testing.

  Element Insertion and Editing

    - ATX heading subtree promotion and demotion via M-S-LEFT, and
      M-S-RIGHT.
    - ATX heading subtree moving up and down via M-S-UP and
      M-S-DOWN.
    - Convert inline links to reference links when
      markdown-insert-reference-link-dwim is used when the point is at
      an inline link.

  Customizable Features

    - Allow linking to multiple stylesheets in markdown-css-paths
      list. Use stylesheets for both preview and export. Previous
      markdown-css-path (singular) is now deprecated.
    - Customizable default unordered list marker via
      markdown-unordered-list-item-prefix.
    - Add asymmetric ATX heading adornment option
      markdown-asymmetric-header.

  Font Lock

    - Separate highlighting for Markdown markup characters (asterisks,
      underscores, backquotes, etc.) to aid in readability.
    - General font lock improvements for comments, code blocks,
      blockquotes, headings, horizontal rules, bold, italics
    - Font lock for bold, italics, and LaTeX math work inside block
      elements such as headings and blockquotes.
    - Font lock for <kbd> tags.

  GFM

    - Support GFM-style code blocks in markdown-mode (as well as
      gfm-mode).
    - New function markdown-electric-backquote will prompt for a
      language name for GFM code blocks. This can be disabled by
      customizing the variable markdown-gfm-use-electric-backquote.
    - Completion of programming language names for GFM code blocks. A
      list of pre-defined languages is included, but this can be
      augmented by setting markdown-gfm-additional-languages.
    - Strikethrough support in gfm-mode.
    - Support for GFM toggling checkboxes mouse-1 or RET. This is
      controlled by a new custom variable,
      markdown-make-gfm-checkboxes-buttons.

  Other Extensions

    - Font lock and filling for Pandoc "fancy list", which use # as
      the list marker.
    - Basic support for filling of definition lists.
    - Support Ikiwiki-style search for wiki links that allows links
      relative to parent directories. Enable this by setting
      markdown-wiki-link-search-parent-directories.

Bug Fixes

    - Fix bug in markdown-complete-region/buffer where level-two
      Setext headings could be confused with horizontal
      rules. Includes a unit test. Thanks to Gunnar Franke for the
      report.
    - Fix filling when a decimal number appears at column zero, which
      could be confused with an ordered list item.
    - Fix buffer-wide markup completion.
    - Fix font-lock for GFM code blocks without language keywords.
    - Improved Setext header insertion to support wide characters.
    - Fix expensive paragraph-separate regular expression.
    - Make comment-auto-fill-only-comments a buffer-local variable,
      which allows for better default filling behavior in cases where
      the global variable is non-nil.
    - Fix Emacs 23 compatibility by checking for
      font-lock-refresh-defaults before calling it.
    - Handle reference definitions when filling paragraphs.
    - Improve filling of list items with indentation.
    - Properly handle footnotes when filling.
    - Fix issues with markdown-footnote-kill and related functions.
    - Improve font lock for fenced code blocks.
    - Avoid avoid overwriting source file when exporting if source
      file has .html extension.
    - Fix and improve ordered list behavior to preserve digit spacing
      and avoid an infinite loop in certain cases. Adjust ordered list
      whitespace when marker digit count increases.
    - Improve reference definition regular expression to avoid matching
      multiple reference links in one line.
    - Allow spaces in fenced code language identifiers.
    - Improve font lock for preformatted blocks and fenced code blocks.
    - Fix out-of-order HTML output.
    - Add console-friendly backspace and tab bindings.
    - Better treatment of files without extensions for wiki
      links. When files have no extensions, don't append a lone
      period.
    - Call looking-back with two arguments for compatibility with
      Emacs 25.1.
    - Make (beginning-of-defun -1) go to next title when point is at
      beginning of defun.
    - Ignore headings in code blocks for font lock.
    - Don't highlight wiki links in code blocks.
    - Don't move to links in code blocks with C-c C-p and C-c C-n.
    - Fix hanging indentation for list items and single-line
      preformatted blocks.
    - Better rejection of false positives for italics with respect to
      other inline elements (inline code and bold).
    - Predicate functions should not modify match data.
    - Use correct list marker from previous list level when using C-u
      M-RET to insert a dedented list item. Prevent an infinite loop
      in some cases.
    - Reduce lag when scrolling or inserting text into large
      files.
    - Avoid confusing tramp errors with malformed wiki
      links.