First of big thanks for the really good FAQ.
While looking at the API (which is working fine) I found one KB part missing. Not sure if by design or not.
If you return an KB with "api.php?action=getFaq&lang=en&recordId=42"
You don't get any reference to the attached document in the REST output. It's not said to be returned by the API, but I think it's should.
Is there a different call to get the document link?