Add Branch Protection Rules to the main branch of this project.

[jtmichelson]

See official GitHub docs: https://docs.github.com/en/repositories/configuring-branches-and-merges-in-your-repository/defining-the-mergeability-of-pull-requests/managing-a-branch-protection-rule#creating-a-branch-protection-rule

• Add rule for at least one separate approver for all PRs.
• Read through protection rules to see if there is anything else we want to add.

[jtmichelson]

Added branch protection rule to main requiring at least one approval before merging, see screepcap below: