A tree-sitter parser is help-wanted

[Freed-Wu]

In order to realize diagnostic like this language server, a tree-sitter parser is needed. A WIP repo is here.
However, I am not familiar with writing a parser and muttrc is a little complex. Any little help from anyone who are good at it or want to take a try is acknowledged.

[Freed-Wu]

The above is tree-sitter, the below is vim syn.