Move MDN drafts to feature spec.

[jpmedley]

I think I mentioned this before. We want to store MDN drafts in the spec repos they support. There are two reasons for this:

• Proximity makes it easier for you to keep it up to date and more likely for you to remember to do so.
• It also makes it more likely that early users, particularly OT participants.

There are arguments for putting it other places, but this is what we want to do for right now.

We're also trying to standardize the name and location of this. What I've done here matches what I did for another feature.

[jpmedley]

@fserb @yiyix

I've moved all of the new documents into the quick reference. Other than the QUICK-REFERENCE.md, this is content that you have already approved.

[yiyix]

I like this idea. LGTM!

[jpmedley]

I mentioned this when I first approached you to do drafts for me. If I recall correctly you agreed to include these here.