doc: add KeyObject to type
The key may optionally be a KeyObject of type secret
It is written in description, but not in type.
Checklist
-
documentation is changed or added -
commit message follows commit guidelines
Do not update/delete: Banner broadcast message test data
Do not update/delete: Notification broadcast message test data
The key may optionally be a KeyObject of type secret
It is written in description, but not in type.