feat(api): create event type CourseUserWasRegistered (#327)

* feat(api): create event type CourseUserWasRegistered (#327)

* file sufix change

Author: kacper-cyra

packages/api/src/module/shared/events/course-user-was-registered.domain-event.ts

@@ -0,0 +1,6 @@
+import type { UserId } from '@/shared/domain.types';
+
+export type CourseUserWasRegistered = {
+  type: 'CourseUserWasRegistered';
+  data: { userId: UserId; courseUserId: string; courseId: string };
+};