[codestyle] shortly explain why we wrap .create() in a transaction

collector/views.py

@@ -48,6 +48,8 @@ class DetailView(generic.DetailView):
 @require_http_methods(["POST"])
 def enter(request: HttpRequest) -> HttpResponse:
     try:
+        # if .create() failed, the transaction is rolled back and we are in a
+        # clean (database) state to handle exceptions
         with transaction.atomic():
             teil = Teil.objects.create(name=request.POST["new_name"])
     except Exception: