Update usage.rst

docs/usage.rst

@@ -21,10 +21,12 @@ To add sorting to a model, your model needs to inherit from ``Sortable`` and hav
 It is also possible to order objects relative to another object that is a ForeignKey.
 
 .. note:: A small caveat here is that ``Category`` must also either inherit from ``Sortable`` or include an ``order`` property which is a ``PositiveSmallInteger`` field. This is due to the way Django admin instantiates classes.
+
 ::
-    from adminsortable.fields import SortableForeignKey
 
     # models.py
+    from adminsortable.fields import SortableForeignKey
+
     class Category(Sortable):
         class Meta(Sortable.Meta):
             pass