Added worker build script

package.json

@@ -11,6 +11,7 @@
     "start": "node scripts/server.js",
     "start:worker": "node scripts/worker-server.js",
     "build": "rimraf dist && webpack --config scripts/webpack.config.prod.js",
+    "build:worker": "rimraf dist && webpack --config scripts/webpack.config.worker.prod.js",
     "prepublishOnly": "npm run build",
     "lint": "eslint src",
     "wait": "rimraf dist && wait-on http://localhost:3000/dist/ffmpeg.dev.js",

scripts/webpack.config.worker.prod.js

@@ -0,0 +1,27 @@
+const path = require('path');
+const common = require('./webpack.config.common');
+
+const genConfig = ({
+  entry, filename, library, libraryTarget,
+}) => ({
+  ...common,
+  mode: 'production',
+  devtool: 'source-map',
+  target: 'webworker',
+  entry,
+  output: {
+    path: path.resolve(__dirname, '..', 'dist'),
+    filename,
+    library,
+    libraryTarget,
+  },
+});
+
+module.exports = [
+  genConfig({
+    entry: path.resolve(__dirname, '..', 'src', 'index.js'),
+    filename: 'ffmpeg.min.js',
+    library: 'FFmpeg',
+    libraryTarget: 'umd',
+  }),
+];