Create onboarding & offboarding checklists for chairs, maintainers, and team members

[scottrigby]

For example, see the checklist in this PR:

• William Caban stepping down as maintainer and from teams #191

[aholbreich]

Two (blocking) to get this done

• where should this list live?
• who takes care of the offboarding?

[scottrigby]

@aholbreich

1. it should live in this open-gitops/project repo
2. the active members of each group (chairs, maintainers, members of each team) should handle both the onboarding and offboarding of new and exiting members of their respective group. See https://github.com/open-gitops/project/blob/main/GOVERNANCE.md for more info about general governance. Perhaps this note about who is responsible should be added to the governance doc as well.

[scottrigby]

Another item to add to maintainer onboarding and offboarding:

• Update CNCF Service Desk "OpenGitOps" project team. It's up to current maintainers to ensure the CNCF Service Desk keeps the "OpenGitOps" project team team there up to date whenever the current maintainers list changes (current list is always up to date here https://github.com/open-gitops/project/blob/main/MAINTAINERS).