Clarify the behavior of "audit.can-author-close-audit"
Summary:
Ref T13631. This option has a behavior other than the behavior implied by the name and documented.
Document the correct behavior, at least. This can likely be removed after T10574.
Test Plan: Read config option help in Config.
Maniphest Tasks: T13631
Differential Revision: https://secure.phabricator.com/D21610