* add tree-sitter-regex
* adapt regex highlights from upstream
* inject regex into elixir sigil_r/2 and sigil_R/2
* generate lang-support docs
* capture interesting nodes in character-ranges
* make $.character_class captures more consistent
* fix fallthrough behavior for character classes
* capture pattern characters as 'string'
* use latest tree-sitter-regex
* set elixir regex injections as combined
* add link to upstream queries
* inject regex in rust into 'Regex::new' raw string literals
