Adds tab for web-public streams in documentation for setting
who can create new streams, as well as some text about why
this is limited to certain roles.
Removes list of actions that can be restricted to full members
due to maintainability concerns for that type of list in the
documentation and replaces it with a short descriptive text
explaining that many settings in Zulip support this restriction.
This commit fixes the following help pages -
- configure-who-can-create-a-stream.md to use "Stream permissions"
subsection and not "Other permissions".
- configure-who-can-invite-to-streams.md to use "Stream permissions"
subsection and not "Other permissions".
- restrict-wildcard-mentions.md to use "Stream permissions" subsection
and not "Organization permissions".
- restrict-bot-creation.md to use "Other permissions" subsection and
not "Organization permissions".
- restrict-visibility-of-email-addresses.md to use "User identity"
subsection and not "Organization permissions".