Implement activity #5
Description
An activity is a generic moniker for work done on a topic:
- An assignment to be completed by students. This will use the "step" mechanism
- A presentation by a lecturer
The details field in an activity is (for now) arbitrary JSON used to capture
activity-specific information. This would include a type of activity; for example:
- Homework assignment
- In-class lecture
- In-class lab
- Student presentation