Mobile Editor Take 1

This is going to have to be iterated over a zillion times, but it's high time we had a mobile view for the code editor. It's a particularly challenging view because there is so much potential UI. Some of it is cut, some of it is buried a little bit, some is the same. And there is some additional UI as well, like being able to zoom in and out of the preview.

keyboard shortcuts: L or F like Z toggle zoom post comment