text: Title: Code listing for app.py in "look” Tutorial has a bug
  Body: In the [Serving images](https://falcon.readthedocs.io/en/stable/user/tutorial.html#serving-images) section, the code listing for `app.py` tries to import the `images` module as `import images`. I believe this should be `from look import images` or depending on one's preferences `import look.images` and refactor references to `images` as `look.images`. I prefer the former:
  
  ```python
  import os
  
  import falcon
  
  from look import images
  
  
  def create_app(image_store):
      api = falcon.API()
      api.add_route('/images', images.Collection(image_store))
      api.add_route('/images/{name}', images.Item(image_store))
      return api
  
  
  def get_app():
      storage_path = os.environ.get('LOOK_STORAGE_PATH', '.')
      image_store = images.ImageStore(storage_path)
      return create_app(image_store)
  ```
  