Add tree-sitter-markdown grammar

[archseer]

https://github.com/ikatyang/tree-sitter-markdown

[lightningx10]

What's going on here? It seems like no one has managed to get this working.

I've cloned in the tree-sitter-markdown in the helix-syntax/languages/ directory, and added the following entry to languages.toml

[[language]]
name = "markdown"
scope = "source.md"
file-types = ["md"]
roots = []

But helix still cannot render the syntax highlighting, which is strange considering it's meant to be automatic at runtime. I'm not sure what to do. Is there something that I'm missing?

[lightningx10]

I've seemingly been able to get it to compile, I also added some more files into runtime/queries/markdown/* files of the previous attempt at a patch. It all worked and compiled, but if there's any mention of code_block anywhere in there then the program will fail at runtime. Not sure what causes this. After removing code_block from there, helix will be able to load markdown, but no syntax highlighting will be drawn making me think that I'm missing something still. Maybe there's more to be done in the runtime/queries section?

[archseer]

The problem is that the grammar is unstable and can panic: nvim-treesitter/nvim-treesitter#872 (comment)

Until that's resolved we can't really proceed.