Geo: Validate Blob Replicator Strategy doc section

Problem

It is likely that we've missed something in https://docs.gitlab.com/ee/development/geo/framework.html#blob-replicator-strategy after closing many small issues.

Proposal

• Double-check that you would actually succeed at adding Geo support to a new blob if you just follow the doc.
• Hopefully we have sufficient tests and documentation by now. If there is a big gap, then either add them, or raise discussions or issues

What does success look like, and how can we measure that?

For now, while we're under development and feature flag (the easy way):

• Poke around the code we've added for replicating Package Files and compare it to what we have documented in https://docs.gitlab.com/ee/development/geo/framework.html#blob-replicator-strategy
• It should seem to match up

What is the type of buyer?

• Premium
• Ultimate