Documentation/bug: Enable the bot as a required check

Even though the bot is installed, it won't be available as a status check to be "required" until the first pull request. Thus any subsequent pull requests might be free to merge (thus I call it a 'bug' if a CLA is a legal requirement)

Repo owners need to "prime" their repos first, so the Adobe CLA bot is available in `Settings -> Branches -> Branch protection rules -> (master) -> Edit`. Only after it is available, then can it be checked (thus it will be Required). This needs to be a documentation thing for repos that have it enabled, perhaps file an issue automatically or PR (not sure how that would work).

See screenshot below:


Start with the GitHub branch protection path described in the issue and review the screenshot showing the Adobe CLA bot check. Update the repository documentation for repos using the bot so owners know to prime the repository with an initial pull request and then mark the CLA check as required; document how this guidance should be surfaced if the project specifies that.

Written by the indexing model from the issue text.