Fixed #8693: Fixed formatting of the "null" argument for model fields

git-svn-id: http://code.djangoproject.com/svn/django/trunk@8737 bcc190cf-cafb-0310-a4f2-bffc1f526a37

docs/topics/db/models.txt

@@ -143,6 +143,7 @@ optional. They're fully explained in the :ref:`reference
 ones:
 
     :attr:`~Field.null`
+
         If ``True``, Django will store empty values as ``NULL`` in the database.
         Default is ``False``.
 
@@ -744,4 +745,4 @@ bindings. This is for the sake of consistency and sanity.)
 
 A final note: If all you want to do is a custom ``WHERE`` clause, you can use
 the :meth:`~QuerySet.extra` lookup method, which lets you add custom SQL to a
-query.
\ No newline at end of file
+query.