3. Document Geo installation on staging.gitlab.com

One the deployment to staging.gitlab.com is complete, we must document how this was done and what steps are involved so that it's easy to address or troubleshoot at a later date.

• Summary of what exists should be made on the Geo Team Handbook Page
• Full description made part of the runbooks repo (https://gitlab.com/gitlab-com/runbooks/blob/master)
• Record how to request a planned failover on staging