CommonMark compliant Markdown formatter

 Mdformat is an opinionated Markdown formatter that can be used to
 enforce a consistent style in Markdown files.
 .
 Mdformat is a Unix-style command-line tool as well as a Python
 library.
 .
 The features/opinions of the formatter include:
 .
  * Consistent indentation and whitespace across the board
  * Always use ATX style headings
  * Move all link references to the bottom of the document (sorted by
    label)
  * Reformat indented code blocks as fenced code blocks
  * Use 1. as the ordered list marker if possible, also for noninitial
    list items