I know a bit about how to use tree-sitter, but npm install does not work in this project, and tests are failing

Wow, thanks a lot, now we have something to work on.

Is there any contribution guide? I cloned the project and tried to build it locally, but it does not look so simple

So, essentially, the primary reason for using hashed globals is to create a separate global for each index. Which will help, only if you have quite a big table with lots of indexes, and a high-load application.