Document setting up MEDIA_ROOT in the Django integration docs

An out-of-the-box Django project is not configured to serve user-uploaded files from MEDIA_ROOT; this needs to be added manually as per https://docs.djangoproject.com/en/1.9/howto/static-files/#serving-files-uploaded-by-a-user-during-development . Fixes #2100

docs/getting_started/integrating_into_django.rst

@@ -82,6 +82,19 @@ The URL paths here can be altered as necessary to fit your project's URL scheme.
 
 In this case, this should be placed at the end of the ``urlpatterns`` list, so that it does not override more specific URL patterns.
 
+Finally, your project needs to be set up to serve user-uploaded files from ``MEDIA_ROOT``. Your Django project may already have this in place, but if not, add the following snippet to ``urls.py``:
+
+.. code-block:: python
+
+    from django.conf import settings
+    from django.conf.urls.static import static
+
+    urlpatterns = [
+        # ... the rest of your URLconf goes here ...
+    ] + static(settings.MEDIA_URL, document_root=settings.MEDIA_ROOT)
+
+Note that this only works in development mode (``DEBUG = True``); in production, you will need to configure your web server to serve files from ``MEDIA_ROOT``. For further details, see the Django documentation: `Serving files uploaded by a user during development <https://docs.djangoproject.com/en/1.9/howto/static-files/#serving-files-uploaded-by-a-user-during-development>`_ and `Deploying static files <https://docs.djangoproject.com/en/1.9/howto/static-files/deployment/>`_.
+
 With this configuration in place, you are ready to run ``./manage.py migrate`` to create the database tables used by Wagtail.
 
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