* PLT-1626 Stopped breaking up hyphenated hashtags when highlighting search terms
* Made hashtag search highlighting case independent
* PLT-1424 Improved search highlighting when searching for CJK characters
* PLT-1473 Added search term highlighting to single-line code blocks
* PLT-1473 Added search term highlighting to code blocks that don't use syntax highlighting
* PLT-1483 Added proper highlighting of at mentions
* Fixing formatting
* Removed MattermostLexer since it was exactly the same as the default marked one
* Updated list autonumbering to always start numbering from the first item's number
