Add a license
As GitLab notes, this codebase does not have a license, and so defaults to "all rights reserved"
Read more on choosealicense.com
choosealicense.com has a list of open source licenses with descriptions. tree-sitter-javascript
, tree-sitter-rust
, etc use the MIT license. tree-sitter-elixir
uses the Apache 2.0 License. Ultimately, the choice is yours!