* Fixed: Preview becoming plain text when clicking on hyperlinks.
* Fixed: Incorrect CLI utility behaviour when a MacDown instance is running.
* Fixed: Crash on resource lookup failures.
* Enhancement: Blockquote and indentation shortcuts now work for empty lines.
* Enhancement: Add a class attribute to the TOC HTML list for styling.
* Enhancement: Always add "language-*" class to code blocks, even if syntax is
  not specified, as recommended by Prism.