There are a couple cases where the comment highlights
will match things that aren't necessary a tag.
For example in Rust, when commenting a block that deals with
generics (generics are declared as `T: Type`),
this may be distracting.
So, instead of highlighting all tags, we can restrict
to highlighting the explicit keywords.
Ref https://github.com/stsewd/tree-sitter-comment/issues/14
