Hooks on treesit parse refresh

[Abin Simon]

I was adding support for builtin treesit to one of my packages,
scopeline.  https://github.com/meain/scopeline.el

The package makes use of these hooks in elisp-tree-sitter to run when a
tree-sitter tree refresh has happened:
- tree-sitter-after-first-parse-hook
- tree-sitter-after-change-functions

I was going through treesit code, but could not find anything
similar. `treesit-explore' seem to add a hook to `post-command-hook' but
wanted to check if there was something more specific that I could use
instead.