Additional, post-copy setup from `spaid` (as instructions)

[lwjohnst86]

e.g. from here: https://github.com/seedcase-project/spaid/blob/main/bin/spaid_gh_set_repo_settings or https://github.com/seedcase-project/spaid/blob/main/bin/spaid_gh_ruleset_basic_protect_main for ruleset protection