docs/lists: add piglit mailing list

Signed-off-by: Brian Paul <brianp@vmware.com>
diff --git a/docs/lists.html b/docs/lists.html
index d89bcff..e415fc9 100644
--- a/docs/lists.html
+++ b/docs/lists.html
@@ -32,6 +32,9 @@
 target="_parent">mesa-announce</a> - announcements of new Mesa
 versions are sent to this list.  Very low traffic.</p>
 </li>
+<li><p><a href="http://lists.freedesktop.org/mailman/listinfo/piglit"
+target="_parent">piglit</a> - for Piglit (OpenGL driver testing framework) discussion.</p>
+</li>
 </ul>
 
 <p>