Add note to PEP 101 about updating the "Python Documentation by Version" page.

pep-0101.txt

@@ -609,6 +609,16 @@ with RevSys.)
     page itself.  So you can simply follow the link above, click on the
     "Edit this page" link, and make your changes as needed.  How convenient!
 
+  - If appropriate, update the "Python Documentaiton by Version" page:
+
+      https://www.python.org/doc/versions/
+
+    This lists all releases of Python by version number and links to their
+    static (not built daily) online documentation.  There's a list at the
+    bottom of in-development versions, which is where all alphas/betas/RCs
+    should go.  And yes you should be able to click on the link above then
+    press the shiny, exciting "Edit this page" button.
+
   - Other steps (other update for new web site)??
 
 Now it's time to write the announcement for the mailing lists.  This is the