Version 0.4.6

• 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 a language-* class to code blocks, even if syntax is
  not specified (language-none), as recommended by Prism.