Support prod and dev modes.

package.json

@@ -3,7 +3,7 @@
   "version": "0.0.1",
   "description": "Apple II Emulator in JavaScript",
   "scripts": {
-    "build": "webpack",
+    "build": "webpack --mode=production",
     "index": "scripts/index.pl > json/disks/index.js",
     "lint": "eslint js",
     "start": "webpack-dev-server"

webpack.config.js

@@ -3,7 +3,6 @@ const path = require('path');
 
 module.exports =
 {
-    mode: 'development',
     devtool: 'source-map',
     entry: {
         main2: path.resolve('js/main2.js'),