chore: move build scripts into build folder

build/webpack.release.js

@@ -0,0 +1,14 @@
+const webpack = require('webpack')
+
+exports = require('./webpack.base')
+
+exports.mode = 'production'
+exports.output.filename = 'eruda.js'
+exports.devtool = 'source-map'
+exports.plugins = exports.plugins.concat([
+  new webpack.DefinePlugin({
+    ENV: '"production"'
+  })
+])
+
+module.exports = exports