Explain how we contruct the spawner

tljh/user_creating_spawner.py

@@ -35,7 +35,11 @@ class CustomSpawner(SystemdSpawner):
         return super().start()
 
 cfg = configurer.load_config()
+# Use the jupyterhub-configurator mixin only if configurator is enabled
+# otherwise, any bugs in the configurator backend will stop new user spawns!
 if cfg['services']['configurator']['enabled']:
+    # Dynamically create the Spawner class using `type`(https://docs.python.org/3/library/functions.html?#type),
+    # based on whether or not it should inherit from ConfiguratorSpawnerMixin
     UserCreatingSpawner = type('UserCreatingSpawner', (ConfiguratorSpawnerMixin, CustomSpawner), {})
 else:
     UserCreatingSpawner = type('UserCreatingSpawner', (CustomSpawner,), {})