Splitted classes into files

index.html

@@ -7,6 +7,10 @@
             padding: 0;
         }
     </style>
+    <script src="Key.js"></script>
+    <script src="Intro.js"></script>
+    <script src="Score.js"></script>
+    <script src="Bar.js"></script>
     <script src="index.js"></script>
 </head>