Tree-sitter grammar for Nushell

[WIP] nushell grammar for tree-sitter

goals (brainstorming)

Ability to serve as a parser for a repl
Ability to work in editors that support tree-sitter (hx, nvim, others)
Ability to work in rust
Fast
Ability to be utilized for syntax highlighting
...

installation guide

for neovim users, please have a look at installation/neovim.md
for helix users, please have a look at installation/helix.md

contributing

see instructions