documentation update

src/shared/states.guard.ts

@@ -19,6 +19,8 @@ export class StatesGuard implements CanActivate {
     private gameRepository: Repository<GameEntity>,
   ) {}
 
+  // Checks the state for gameId and grants access if it matches the criteria
+  // allowed states are CREATED, STARTED, PAUSED, ENDED
   async canActivate(context: ExecutionContext): Promise<boolean> {
     // get game states that are allowed access, identified by @GameStates('state') decorators in controllers
     const states = this.reflector.get<string[]>('states', context.getHandler());