Bug Fixes

* Front-matter detection for file using line endings other than LF.
* Code blocks with certain languages causes exceptions when being highlighted.

Enhancements

* You can now configure what marker MacDown should use when auto-generating unordered
  lists. This only affects the autocompletion rule—all legal markders are still always
  available for manual input.
* Improved error message when user clicks on a link with non-existent target.
* Add `<kbd>` styling to all stylesheets.
* MacDown now recognise `.markdown` as valid Markdown file extension.
* MathJax’s processing prompt is now hidden, giving the preview a cleaner interface.