I cloned the repo and created a new branch. What else is needed?
Make your changes, and create a pull request.
https://docs.github.com/en/pull-requests/collaborating-with-pull-requests/proposing-changes-to-your-work-with-pull-requests/creating-a-pull-request-from-a-fork
You need to fork the repo, add your fork as a git remote, then push your changes to your fork, then github will show a button to make a pull request against the main repo.
There are only a few people who can push directly to the main repo, and that is on purpose.
BTW, once you create the fork, you can edit files directly on Github, without needing to clone and push.
I still don’t know what strategy to use with filmic latitude and contrast (and so I can’t update the docs). Most of the time I don’t touch filmic at all - the V6 defaults were extremely well for my typical subjects (low contrast, low dynamic range).