Create the use case chain for the game loop task: Use Case Diagram
UCD-001, User Stories US-001 (two stories), Use Case UC-001 and System
Sequence Diagram SSD-001, all Proposed. Link them from MIL-003.
Review MIL-003 (RC-006, Go) and accept it. Add the new artifacts to the
Traceability Matrix and register UCD, US, UC and SSD in the artifact
registry.
Refs #13