Collate existing evaluation outcome docs

[j08lue]

We produced a lot of documentation for the last phase of our architecture review / evaluation of KeyCloak and Custos.

Some of it is complete, some stubs, some in Google Docs, some in Markdown files in https://github.com/NASA-IMPACT/veda-auth-central/tree/main/docs.

The goal here is to bring these docs together somewhere so they can become part of the documentation for ESDS.