Update containers.rst
When creating a container the documentation stated that config source type should be image and an image key should be present to define the image. However this should be {'type': 'image', 'alias': '...'}.
@@ -107,7 +107,7 @@ container.
.. code-block:: python
- >>> config = {'name': 'my-container', 'source': {'type': 'image', 'image': 'ubuntu/trusty'}}
+ >>> config = {'name': 'my-container', 'source': {'type': 'image', 'alias': 'ubuntu/trusty'}}
>>> container = client.containers.create(config, wait=True)
>>> container.start()
>>> container.freeze()
