Make documentation valid HTML

documentation.html

@@ -23,7 +23,7 @@
 <li><a href="#d5">Proxy support</a></li>
 <li><a href="#d6">YouTube formats</a></li>
 <li><a href="#d7">Output template</a></li>
-</li>
+</ul>
 </div>
 
 <h1 id="d1">Getting started</h1>
@@ -71,7 +71,7 @@
 
 <h1 id="d5">Proxy support</h1>
 
-<p>youtube-dl supports downloading videos through a proxy, by setting the <em>http_proxy</em> environment variable to the proxy URL, as in <tt>http://proxy_machine_name:port/</tt>.</p>
+<p>youtube-dl supports downloading videos through a proxy, by setting the <em>http_proxy</em> environment variable to the proxy URL, as in <code>http://proxy_machine_name:port/</code>.</p>
 
 <h1 id="d6">YouTube formats</h1>