Add editor languages

[DanielleHuisman]

• Text
• JSON
• VHDL
• Verilog
• Haskell

Most non-default languages in VS Code are made using TextMate language definitions (.tmLanguage). Unfortunately, these are not supported in the Monaco editor. There is a project (possibly outdated) that adds TextMate support to Monaco, but this requires (heavy) modifications to Monaco and might not receive updates regularly. Alternatively, the TextMate language definitions could be converted to the native Monaco format.

[DanielleHuisman]

Something might have changed, because Verilog (.v) files do have syntax highlighting. I have not yet tested the other languages.