Link to consensual_youtube.py code docs instead of PR

As suggested in apache/www-site#373 (comment)

examples/youtube-html/with-youtube-api.html

@@ -45,7 +45,7 @@ <h1>Usage</h1>
         </div>
         <h2>Pelican</h2>
         <div>
-                If you're using the <a href="https://github.com/apache/infrastructure-pelican">ASF Pelican tools</a> you can use the <a href="https://github.com/apache/infrastructure-pelican/pull/52">consensual_youtube</a> plugin.
+                If you're using the <a href="https://github.com/apache/infrastructure-pelican">ASF Pelican tools</a> you can use the <a href="https://github.com/apache/infrastructure-pelican/blob/master/plugins/consensual_youtube.py#L20">consensual_youtube</a> plugin.
         <div>
         <script>
         function loadScript() {