bpo-33251: Update documentation to reflect change. (GH-6446) (#6583)

Author: chrBrd

Doc/library/configparser.rst

@@ -1120,6 +1120,11 @@ ConfigParser Objects
       given *section*.  Optional arguments have the same meaning as for the
       :meth:`get` method.
 
+   .. versionchanged:: 3.8
+      Items present in *vars* no longer appear in the result.  The previous
+      behaviour mixed actual parser options with variables provided for
+      interpolation.
+
 
    .. method:: set(section, option, value)