Update the Gitlab::Markdown docs

lib/gitlab/markdown.rb

@@ -3,31 +3,7 @@ require 'html/pipeline'
 module Gitlab
   # Custom parser for GitLab-flavored Markdown
   #
-  # It replaces references in the text with links to the appropriate items in
-  # GitLab.
-  #
-  # Supported reference formats are:
-  #   * @foo for team members
-  #   * #123 for issues
-  #   * JIRA-123 for Jira issues
-  #   * !123 for merge requests
-  #   * $123 for snippets
-  #   * 1c002d for specific commit
-  #   * 1c002d...35cfb2 for commit ranges (comparisons)
-  #
-  # It also parses Emoji codes to insert images. See
-  # http://www.emoji-cheat-sheet.com/ for a list of the supported icons.
-  #
-  # Examples
-  #
-  #   >> gfm("Hey @david, can you fix this?")
-  #   => "Hey <a href="/u/david">@david</a>, can you fix this?"
-  #
-  #   >> gfm("Commit 35d5f7c closes #1234")
-  #   => "Commit <a href="/gitlab/commits/35d5f7c">35d5f7c</a> closes <a href="/gitlab/issues/1234">#1234</a>"
-  #
-  #   >> gfm(":trollface:")
-  #   => "<img alt=\":trollface:\" class=\"emoji\" src=\"/images/trollface.png" title=\":trollface:\" />
+  # See the files in `lib/gitlab/markdown/` for specific processing information.
   module Markdown
     # Provide autoload paths for filters to prevent a circular dependency error
     autoload :AutolinkFilter,               'gitlab/markdown/autolink_filter'