[User Documentation] Guidance for setting up permissions in GitLab

Background:

Customers are often lost on best way to set up users, user groups, and permissions to optimize for PoLP.

Proposal:

Develop guidance on how to set up permissions with respect to users, groups, inheritance and other settings that highlights various approaches and explain tradeoffs.

Plan:

• Discovery with PS, Orgs, Auth
• Develop documentation that factors in these authorization components with respective graphs and tables to highlight tradeoffs
• Feedback by Corporate Security

Take into consideration:

• Roles (Default, Customer), User Provisioning, Inheritance, Groups, "User Groups", Group and Project Permissions