Drop extraneous changes.

Author: ericsnowcurrently

Doc/library/concurrent.interpreters.rst

@@ -31,7 +31,10 @@ Actual concurrency is available separately through
    :class:`~concurrent.futures.InterpreterPoolExecutor`
       combines threads with interpreters in a familiar interface.
 
-    .. XXX Add references to the upcoming HOWTO docs in the seealso block.
+   :ref:`multiple-interpreters-howto`
+       how to use multiple interpreters
+
+   .. XXX Add a reference to the upcoming concurrency HOWTO doc.
 
    :ref:`isolating-extensions-howto`
        how to update an extension module to support multiple interpreters