Fix malformed note directives.

docs/ref/contrib/postgres/forms.txt

@@ -150,6 +150,7 @@ HStoreField
         submission to the server.
 
     .. note::
+
         On occasions it may be useful to require or restrict the keys which are
         valid for a given field. This can be done using the
         :class:`~django.contrib.postgres.validators.KeysValidator`.

docs/topics/migrations.txt

@@ -604,6 +604,7 @@ of three things ``(path, args, kwargs)``:
   ``__init__`` method. Every value should itself be serializable.
 
 .. note::
+
     This return value is different from the ``deconstruct()`` method
     :ref:`for custom fields <custom-field-deconstruct-method>` which returns a
     tuple of four items.