fix path to socket.io

slidenotes/notes.html

@@ -62,7 +62,7 @@
     </div>
     <div id="notes"></div>
 
-    <script src="socket.io/socket.io.js"></script>
+    <script src="/socket.io/socket.io.js"></script>
 
     <script>
     var socketId = '{{socketId}}';