generate dartisans from playlist, keep everything up to date

src/site/dartisans/index.markdown

 ---
 layout: default
 title: "Dartisans: The Dart show"
 description: "The Dartisans show features special guests from the Dart team and community. Watch videos or subscribe to the podcast."
 ---
 
 {% injectdata episodes dartisans/episodes.yaml %}
 
 # Dartisans — The Dart show and podcast
 
 This page archives recordings of Dartisans, the video show
 and podcast about Dart. Dartisans is a semi-regular
 broadcast featuring special guests from the Dart team and the community.
 
 You can also subscribe to an audio podcast of Dartisans,
 either with a
 <a href="/dartisans/podcast-feed"
   title="Subscribe to Dartisans podcast feed"> <i class="icon-rss"> </i> direct link</a>
 or with
 <a href="http://itunes.apple.com/us/podcast/dartisans-dart-programming/id546874773?mt=2"
   title="Subscribe to Dartisans podcast with iTunes"> <i class="icon-rss"> </i> iTunes</a>.
 
 {% for episode in page.episodes.episodes %}
 
 {% capture link %}dartisans-ep-{{episode.num}}.html{% endcapture %}
 
 <div class="row" style="margin-bottom:1em">
   <div class="span2">
-    <a href="{{ link }}"><img style="margin-top:9px; box-shadow: 5px 5px 10px #CCC" src="dartisans-{{episode.num | format_num: "%02d" }}-thumb.jpeg"></a>
+    <a href="{{ link }}"><img style="margin-top:9px; box-shadow: 5px 5px 10px #CCC" src="{{episode.thumbnail}}"></a>
   </div>
   <div class="span10">
-    <h3><a href="{{ link }}">Ep. {{ episode.num}}: {{ episode.subtitle }}</a></h3>
+    <h3><a href="{{ link }}">Ep. {{ episode.num }}: {{ episode.subtitle }}</a></h3>
     
     <p>{{ episode.description }}</p>
 
     <p>Aired {{episode.pubdate}}.</p>
   </div>
 </div>
 
 {% endfor %}