Implement Curriculum schema

[dyf]

• [ ] Add the generic Curriculum schema
• [ ] Add an example that uses the basic Task from #2

[bruno-f-cruz]

Both links provided in #2 also contain examples that may be informative.

[hanhou]

Example from Han

• Curriculum schema
• Example curriculum
• Unit test: serialization and deserialization

[bruno-f-cruz]

Closing this. We should replace it with a workshop-like session at some point.