added webpack setup

index.html

@@ -1,6 +1,6 @@
 <html>
   <body>
     <canvas id="canvas" width="400" height="600" style="border: 1px solid #333"></canvas>
-    <script src="main.js"></script>
+    <script src="http://localhost:8080/dist/bundle.js"></script>
   </body>
 </html>