build: cleanup webpack config

webpack.prod.js

@@ -0,0 +1,31 @@
+const { merge } = require('webpack-merge');
+const common = require('./webpack.common.js');
+const path = require('path');
+const HtmlWebpackPlugin = require('html-webpack-plugin');
+const CopyPlugin = require('copy-webpack-plugin');
+
+module.exports = merge(common, {
+  mode: 'production',
+  output: {
+    path: path.resolve(__dirname, './build'),
+    filename: '[name].[chunkhash].js',
+    chunkFilename: '[id].[chunkhash].chunk.js',
+    clean: true
+  },
+  plugins: [
+    new HtmlWebpackPlugin({
+      template: path.resolve(__dirname, './public/index.html')
+    }),
+    new CopyPlugin({
+      patterns: [{
+          from: 'public/icons',
+          to: 'icons'
+        },
+        {
+          from: 'public/offline-images',
+          to: 'offline-images'
+        }
+      ]
+    })
+  ]
+});