coaches resources tab

[pdpinch]

As an instructor, I would like to direct to coaches to some teachers-only, related resources in my course. I can sort of do this now using a hidden_from_students chapter in the course, but it would be better to have something available through the coaches dashboard, like a "resources" tab.

The big implementation question here is how the content for the resources tab might be authored. One simple measure would be to limit the resources tab to a fixed set of links, e.g discussion board in master course, "teachers guide" chapter of the master course, help desk, etc.