Update PEP Index URL to canonical form (#162)

* Update to canonical PEP URL

* Remove trailing slash

Co-authored-by: Ezio Melotti <[email protected]>

---------

Co-authored-by: Ezio Melotti <[email protected]>

Author: hugovk

templates/indexsidebar.html

@@ -21,7 +21,7 @@ <h3>{% trans %}Download{% endtrans %}</h3>
 <h3>{% trans %}Other resources{% endtrans %}</h3>
 <ul>
   {# XXX: many of these should probably be merged in the main docs #}
-  <li><a href="https://www.python.org/dev/peps/">{% trans %}PEP Index{% endtrans %}</a></li>
+  <li><a href="https://peps.python.org">{% trans %}PEP Index{% endtrans %}</a></li>
   <li><a href="https://wiki.python.org/moin/BeginnersGuide">{% trans %}Beginner's Guide{% endtrans %}</a></li>
   <li><a href="https://wiki.python.org/moin/PythonBooks">{% trans %}Book List{% endtrans %}</a></li>
   <li><a href="https://www.python.org/doc/av/">{% trans %}Audio/Visual Talks{% endtrans %}</a></li>