Fix docstring for contextfactory; mentioned old contextmanager name.
diff --git a/Lib/contextlib.py b/Lib/contextlib.py
index b2902a4..4e3b9c2 100644
--- a/Lib/contextlib.py
+++ b/Lib/contextlib.py
@@ -53,7 +53,7 @@
 
     Typical usage:
 
-        @contextmanager
+        @contextfactory
         def some_generator(<arguments>):
             <setup>
             try: