This repo contains shared actions and workflows that are consumed by the other uid2 workflows.
This simplifies the management and maintenance of the workflows.
If you're trying to do something that should be simple, but can't find something that quite supports what you're trying to do, the GitHub Script action gives you an authenticated GitHub API client and you can just provide a JavaScript script. For an example, see the "Tag commit" step in the Commit, PR, and Merge shared action.
If you use this and the script gets complicated, consider trying to find a simpler approach, or putting the script somewhere it can be maintained/tested outside of the YAML file.