Ownership guide

This is a work in progress, but this should get *extensive* review, so I'm putting it up early and often.

This is the start of a draft of the new 'ownership guide,' which explains ownership, borrowing, etc. I'm feeling better about this framing than last time's, but we'll see.
Agreed, @huonw 

at the weekly meeting, we breifly disucssed this, and many support using real names, but the last time i wrote odcs with real names, there was some pushback. It's a convention I'm sure we'll addres someday, but your wording works for now.