fix incorrect directory reference

index.html

@@ -321,6 +321,7 @@ linkify( 'a' );
 			} );
 
 			// If we're runnning the notes server we need to include some additional JS
+			// TODO Is there a better way to determine if we're running the notes server?
 			if( window.location.host === 'localhost:1947' ) {
 				head.js( 'socket.io/socket.io.js', 'plugin/slidenotes/client.js' );
 			}