We should add documentation covering all CRDs that are specific to the Sail operator (e.g. a config reference) - including a brief description of what each field is for. For example, "Istio", "IstioRevision" and any other CRDs we created.

This does not need to cover upstream Istio configuration fields, though a pointers or links to upstream Istio configuration references would be helpful where applicable (e.g. what goes in the values field, etc).

This can be generated or maintained in any manner, but needs to be accessible from the main Sail operator readme.

The target readers of this documentation includes:

• Istio community members and others potential community users
• Red Hat doc writers, who may reuse the content for our product docs
• Customer users looking to gain experience with the Sail operator (this request came from a customer)

Note: This could help with: https://issues.redhat.com/browse/OSSM-5895

Acceptance Criteria:

• As part of `make gen`, generate an API reference from our CRDs/docstrings