Add workhorse image scaler runbook
We're looking to deploy a new image scaler part of workhorse to a wider audience, so we are preparing alerts and runbooks to help operating it.
- Epic: gitlab-org&3822
- Related implementation MR: gitlab-org/gitlab-workhorse!603 (merged)
- Related alerts MR: !2787 (merged)
Edited by Matthias Käppler