Some formatting changes for showing auth provider config guidance
Ref T7667. On the road to locking the auth config, also clean up some minor UI issues:
- Only show the warning about not Phacility instance auth if the user isn't a manager (see next diff).
- When rendering more than one warning in the guidance, add bullets.
- I didn't like the text in the auth.config-lock config setting.
Test Plan: Loaded the page, saw more reasonable-looking guidance:
Reviewed By: epriestley
Maniphest Tasks: T7667
Differential Revision: https://secure.phabricator.com/D20400