Document CollegeHumor and arte.tv

documentation.html

@@ -70,6 +70,8 @@ Unsupported, see https://github.com/rg3/youtube-dl/issues/300
 <li>myvideo.de.</li>
 <li>The Daily Show / Colbert Nation.</li>
 <li>The Escapist.</li>
+<li>CollegeHumor.</li>
+<li>arte.tv.</li>
 <li>A generic downloader that works in some sites.</li>
 </ul>