Adjust docstring for Locator constructor.

pystache/locator.py

@@ -21,9 +21,9 @@ class Locator(object):
 
         Arguments:
 
-          extension: the template file extension.  Pass False for no
-            extension (i.e. to use extensionless template files).
-            Defaults to the package default.
+          extension: the template file extension, without the leading dot.
+            Pass False for no extension (e.g. to use extensionless template
+            files).  Defaults to the package default.
 
         """
         if extension is None: