moved into lessons folders, added code folder for teachers

It adds the code folder so teachers have a copy of what students have for each lesson, but it kludges up the lesson portion with a bunch of horrible relative css paths, repetitive menus, etc. I don't think this is a workable model going down the road.

I think we need an app to handle the lessons/schedule section, and a different repo that has the code ready for teachers to pull up in class.