Update AWS HA diagram
Overview
The architecture diagram in Installing GitLab HA on Amazon Web Services recommends setting up a read only Gitaly server. This has caused some confusion, as discussed in this issue because there doesn't seem to be any documentation on how to set up a read only Gitaly server.
From what I understand, this diagram may have been created by @dtacheny and is based on a solution that Professional Services has implemented. However, there doesn't seem to be any public documentation on how to set this up and the Support team seems to be lacking information on how to configure and support it.
Recommendation
My recommendation for now is to remove the read only Gitaly server from the diagram.