Update website.ad

Warn about the podling status file format.
diff --git a/pages/guides/website.ad b/pages/guides/website.ad
index 66de50c..1fe1086 100644
--- a/pages/guides/website.ad
+++ b/pages/guides/website.ad
@@ -29,6 +29,8 @@
 
 Podling status files are maintained in SVN, and you should continue to maintain them at https://svn.apache.org/repos/asf/incubator/public/trunk/content/projects/
 
+Podling status files are in a particular XML format which the CLutch Analysis expects.
+
 Extra podling yaml files that communicate with Whimsy are maintained in SVN, and you should maintain them at https://svn.apache.org/repos/asf/incubator/public/trunk/content/podlings/