docs: add qapi-domain syntax documentation

Who documents the documentation?

Me, I guess.

Signed-off-by: John Snow <jsnow@redhat.com>
Message-ID: <20250311034303.75779-63-jsnow@redhat.com>
Acked-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2 files changed