Branch strategies

[jennyhickson]

write some guidelines on handling and updating branches. Potentially including:

• making it clear to merge not rebase when catching up to main
• use of branch of branch to do sequential work and encourage smaller tickets - cherry picking, does deleting the initial branch make a difference on a rebase?
• encourage use of forks as good playgrounds for investigative work.

[james-bruten-mo]

Another thing for this one is the suggestion to setup branch protection rules on main/stable on a fork