Get ready for the CE>EE merge

Let's find out how the process to deploy the docs site would change with the project renames https://gitlab.com/gitlab-org/gitlab-ee/issues/13304#august-26-30

• Determine the URL redirect options. Note that we do need to choose a new path instead of /ce and /ee, probably /gitlab. (This is not a hard requirement for the new repo name change and can wait for a later phase.)
• Change the project names we're pulling from in !532 (merged)

Notes:

• About redirects: is docs.gitlab.com behind a load balancer? Can we redirect at that level? https://gitlab.com/gitlab-com/gl-infra/infrastructure/issues/7663