Improve module comment

celery/task/__init__.py

@@ -3,7 +3,10 @@
     celery.task
     ~~~~~~~~~~~
 
-    This is the old task module, it should not be used anymore.
+    This is the old task module, it should not be used anymore,
+    import from the main 'celery' module instead.
+    If you're looking for the decorator implementation then that's in
+    ``celery.app.base.Celery.task``.
 
 """
 from __future__ import absolute_import