Right now (version 2.1.6), ghostwriter's syntax highlighting doesn't appear to support yaml metadata blocks. Since this kind of frontmatter is now used all over the place by many different markdown parsers (hugo, jekyll, pandoc, knitr just to name a few), I think it would be great if ghostwriter could display these nicely!
Created attachment 178756 [details] Screenshot showing YAML frontmatter formatting Seconding this; it currently parses the first triple dash preceding YAML frontmatter as a horizontal rule and the way things get rendered isn't great.