Added a link to AUTO_UPDATE docs from release notes

docs/releases/1.0.rst

@@ -119,7 +119,7 @@ Search
 ------
 
  * Search view accepts "page" GET parameter in line with pagination
- * Added ``AUTO_UPDATE`` flag to search backend settings to enable/disable automatically updating the search index on model changes
+ * Added :ref:`AUTO_UPDATE <wagtailsearch_backends_auto_update>` flag to search backend settings to enable/disable automatically updating the search index on model changes
 
 
 Routable pages

docs/topics/search/backends.rst

@@ -18,6 +18,8 @@ You can configure which backend to use with the ``WAGTAILSEARCH_BACKENDS`` setti
   }
 
 
+.. _wagtailsearch_backends_auto_update:
+
 ``AUTO_UPDATE``
 ===============