Fixed #3346 -- Documented that search_fields Admin option can use related…

Fixed #3346 -- Documented that search_fields Admin option can use related models. Thanks for the patch, Robert Myers and Gary Wilson

git-svn-id: http://code.djangoproject.com/svn/django/trunk@4392 bcc190cf-cafb-0310-a4f2-bffc1f526a37

docs/model-api.txt

@@ -1408,7 +1408,10 @@ This should be set to a list of field names that will be searched whenever
 somebody submits a search query in that text box.
 
 These fields should be some kind of text field, such as ``CharField`` or
-``TextField``.
+``TextField``. You can also perform a related lookup on a ``ForeignKey`` with 
+the lookup API "follow" notation::
+
+    search_fields = ['foreign_key__related_fieldname']
 
 When somebody does a search in the admin search box, Django splits the search
 query into words and returns all objects that contain each of the words, case