Can we add a link to course site nav menus?

Determine whether we can add a link to the course navigation menu for the following LMSes:

- Sakai
- Moodle
- Blackboard
- D2L

We already know [this is possible in Canvas](https://canvas.instructure.com/doc/api/file.navigation_tools.html).

If this is possible for all LMSes, providing access to activity views via a link in the nav menu could mitigate many of the complexities of developing/linking to activity views.

Next step would be to determine what we'd need to do with our app to get a link in the nav menu.