Updates the main description for the `get-stream-topics` endpoint
so that it is clear that the topics for private streams with protected
history are limited to the topics / messages the user has access to.
And updates that documentation and the help center documentation for
bot permissions / abilities, to clarify that bots have the same
restriction and can only access messages / topics that are sent after
the bot (not the bot's owner) subscribed to the stream.
These files are not Jinja2 templates, so there's no reason that they needed
to be inside `templates/zerver`. Moving them to the top level reflects their
importance and also makes it feel nicer to work on editing the help center content,
without it being unnecessary buried deep in the codebase.
Lauryn Menard
Alex Vandiver
David Rosa
Lauryn Menard