Update app checklist config value

[compwron]

The current value of https://app.doubleunion.org/admin/configurable > Onboarding offboarding checklist goes to https://docs.google.com/document/d/1udA9ygbX8IVop3yD8ZcsmH5_C2C2liznCLDSJvYaSg4/edit which shows "Access denied" for both a member of the members@ email list and the membership@ account. I think this link should go to [REDACTED because it is viewable as view-only when not logged in at all] instead, so I think we should change it to be the doc titled "How to add/remove membership privileges and new membership coordinators" unless the current doc is something that only the board has access to?