[UNIVERSITY-10 Create draft architecture for software architecture coursework]
[UNIVERSITY-11 Сlarify software requirements for software architecture coursework]

Domain model has been updated
[UNIVERSITY-10 Create draft architecture for software architecture coursework]
[UNIVERSITY-11 Сlarify software requirements for software architecture coursework]

Domain model has been updated
[UNIVERSITY-10 Create draft architecture for software architecture coursework]

Activity related API has been updated.
First submission has been done
Registration functionality has been implemented.
It should be refactored, but it works.