Fix/treesitter markup

[roosta]

Fix treesitter markup

• Add new strikethrough option
  • Used only with tree sitter for now, but good to have defined
• Fix missing treesitter markup highlights
  • Fixes issue with markup mentioned in issue Possible missing treesitter support for italic, bold, italic, underline and strikethrough #117 by defining markup highlights, including strikethrough

[MindTooth]

Do we have a good example to test this?

Ed1t: https://stackoverflow.com/a/48406113/182868

[roosta]

I installed the neorg extension, and used this sample hello.norg

This is *bold text*.

This is /italicized text/.

This is -strikethrough-

This is _underline_

[roosta]

can use this snippet to test your term, see if it supports it: echo -e "\e[9mtest\e[0m"

[Sberlos]

This PR fixes all the missing treesitter markup in neorg for me, thank you very much!