fix bad sentence in manual

Author: marijnh

manual.html

@@ -110,7 +110,7 @@ <h2 id="config">Configuration</h2>
       <dt id="option_mode"><code>mode (string or object)</code></dt>
       <dd>The mode to use. When not given, this will default to the
       first mode that was loaded. It may be a string, which either
-      simply names the mode
+      simply names the mode or is
       a <a href="http://en.wikipedia.org/wiki/MIME">MIME</a> type
       associated with the mode. Alternatively, it may be an object
       containing configuration options for the mode, with