LQWiki:User preferences help

I just realized this topic isn't populated ?!?

Maybe someone deleted the Preferences help topic by accident?

This topic is linked to in text near the top of the "Preferences" page for users. I'm not sure if (1) that text should change or (2) this topic should be properly populated... but leaving a prominent help link sitting around unpopulated seemed wrong, so I decided to at least put SOMETHING here.