Keep maintainers in sync in mirrors

Overview

The http-router project is mirrored to https://ops.gitlab.net/gitlab-org/cells/http-router but the permissions for the users are not mirrored. We at least need to have the http-routers with maintainer permissions so that we can merge merge requests in ops, in the scenario where GitLab.com is completely unavailable.

An argument can be made that even SREs should have maintainer access to http-router in ops so that they can merge fixes during incidents but I think starting off with the "real" maintainers of the http-router is best.

GitLab.com	ops.GitLab.net
source	source

Action Items

• Create a new entry in teams for tenant-scale.yml
  • This should specify a field like http_router_maintainers including the usual information we add to the yml file.
• Use the entry above to specify that http_router_maintainers are members with maintainer access
• Update documentation on how to add maintainers to this repository.