Move the "Advanced Configuration" documentation.
Summary: This documentation doesn't really fall under the "Application User Guides" section, it should be moved to "Configuration".
Test Plan: N/A
Reviewers: epriestley, Blessed Reviewers
Reviewed By: epriestley, Blessed Reviewers
Subscribers: epriestley, Korvin
Differential Revision: https://secure.phabricator.com/D9403