chore: separate polyfill

build/webpack.analyser.js

@@ -1,5 +1,5 @@
-const BundleAnalyzerPlugin =
-  require('webpack-bundle-analyzer').BundleAnalyzerPlugin
+const BundleAnalyzerPlugin = require('webpack-bundle-analyzer')
+  .BundleAnalyzerPlugin
 
 exports = require('./webpack.prod')
 

build/webpack.polyfill.js

@@ -0,0 +1,10 @@
+const path = require('path')
+
+module.exports = {
+  mode: 'production',
+  entry: './src/polyfill',
+  output: {
+    path: path.resolve(__dirname, '../dist'),
+    filename: 'eruda-polyfill.js',
+  },
+}