Renaming the default branch from master

[grochocki]

From GitHub:

For existing repositories, renaming the default branch today causes a set of challenges... By the end of the year, we'll make it seamless for existing repositories to rename their default branch. When you rename the branch, we’ll retarget your open PRs and draft releases, move your branch protection policies, and more - all automatically. And, we’re also looking into redirecting users who git fetch or git clone the old branch name to the new branch name (with a warning and instructions to update their local clone), so it’s easy for your contributors to move. You’ll be able to do a rename from GitHub.com, GitHub Desktop, or the CLI.

When support for migrating existing repositories is introduced, we will use this feature to migrate our default branch name from master to main.