[close #198] Add a note about setting MEDIA_URL.

README.rst

@@ -38,6 +38,8 @@ Required
    CKEditor has been tested with django FileSystemStorage and S3BotoStorage.
    There are issues using S3Storage from django-storages.
 
+#. For the default filesystem storage configuration ``MEDIA_ROOT`` and ``MEDIA_URL`` must be set correctly for the media files to work (like those uploaded by the ckeditor widget).
+
 #. Run the ``collectstatic`` management command: ``$ ./manage.py collectstatic``. This'll copy static CKEditor require media resources into the directory given by the ``STATIC_ROOT`` setting. See `Django's documentation on managing static files <https://docs.djangoproject.com/en/dev/howto/static-files>`_ for more info.
 
 #. Add CKEditor URL include to your project's ``urls.py`` file::