reorganize deployment docs for more per-deployment details
Created by: bobheadxi
current work on a refreshed dogfood environment to replace k8s.sgdev.org and a potential demo environment will probably necessitate more documentation about the specifics of each deployment, how to use them, how to troubleshoot/debug them, etc.
This PR is a first step towards that by restructuring each deployment into a section instead of just a list item so that there is more room to add details, and lifts documentation that's true of all deployments (Docker images, general Renovate usage) into a separate section. I've tried to avoid making actual content changes in this PR - this is mostly just moving things around.
There are also a lot of top-level topics in this document which makes it rather hard to read - this PR also creates a few sections like "kubernetes", "testing", etc. to better group them