add superuser and reset make commands

Makefile

@@ -8,6 +8,13 @@ lint:
 	docker exec pigeonhole-backend flake8 .
 	docker exec pigeonhole-frontend npm run lint
 
+superuser:
+	docker exec -it pigeonhole-backend python manage.py createsuperuser
+
+reset:
+	docker image prune -af
+	docker system prune
+
 backendtest:
 	docker exec -it pigeonhole-backend sh /usr/src/app/backend/runtests.sh