Resource Estimator: Ref Arch Kubernetes External Services

Created by: briemcnally

Using the data gathered in https://github.com/sourcegraph/sourcegraph/issues/30765, create a static example / “reference deployments” that specify resource usage and some context about scale for docker compose external services.

Scope:

• Document prototype in google docs
• Share with CE/design for review
• Tech review
• Publish externally