Onboarding for new maintainers and admins #158

We have different teams with different access priviledges. For each tier, rules and expectations should be made clear and onboarding be done for:

• New maintainers and admins.
• Existing ones: A refresher course, especially when rules/expectations have changed over time.

Example: One shall not open feature branch upstream, but always from fork. (And so on...)

Might be relevant:

• https://github.com/astropy/astropy-project/blob/main/policies/adding-new-role-members.md
• https://github.com/astropy/astropy-project/blob/main/policies/permissions.md
• https://github.com/astropy/astropy-project/blob/main/policies/pull-request-review-and-merge.md
• https://www.astropy.org/contribute.html
• https://docs.astropy.org/en/latest/index_dev.html

Open questions:

• How are people in the project currently onboarding their new peers?
• What is working well?
• What can be improved?
• If we generate new documentation and/or policies, where should they live?