We'll extend this in the future with details on what is configurable,
but this at least ensures we don't have a state where they don't
appear in our documentation at all.
This commit includes a new `stream_post_policy` setting,
by replacing the `is_announcement_only` field from the Stream model,
which is done by mirroring the structure of the existing
`create_stream_policy`.
It includes the necessary schema and database migrations to migrate
the is_announcement_only boolean field to stream_post_policy,
a smallPositiveInteger field similar to many other settings.
This change is done to allow organization administrators to restrict
new members from creating and posting to a stream. However, this does
not affect admins who are new members.
With many tweaks by tabbott to documentation under /help, etc.
Fixes#13616.
slefforge
mandepsingh
Tim Abbott
Alex Vandiver
Ryan Rehman
Rishi Gupta
Lyla Fischer