Rename default git branch from master to new git default "main"

[ypid]

• Check if "master" is still used anywhere in the repo and remove it or change it to "HEAD" (meaning the default branch of the git remote).
• Merge all PRs as those PRs would otherwise be closed. ("If the renamed branch is the head branch of an open pull request, this pull request is closed.". Ref: https://docs.github.com/en/repositories/configuring-branches-and-merges-in-your-repository/managing-branches-in-your-repository/renaming-a-branch

From: #483 (comment)

[KristjanESPERANTO]

For step one I just created #495 🙂

Since merging all the PRs would be a major undertaking and you were positive about the idea of working in the develop branch (in #483), I just changed the base of all PRs from master to develop. This way renaming master should have no effect on the PRs.

[ypid]

Sounds good. This also seems to work: https://github.com/opening-hours/opening_hours.js/tree/HEAD/LICENSES

Not sure if that is officially supported. HEAD is an overused term in git. Here it means the default branch of the repository. So I guess we/I rename the master branch to main after the next release. Sounds good?

[KristjanESPERANTO]

Yes, sounds good 👍🙂