fix(@angular-devkit/build-optimizer): comma in webpack example is missing (#108)

Author: stevermeister

packages/angular_devkit/build_optimizer/README.md

@@ -122,7 +122,7 @@ module.exports = {
     rules: [
       {
         test: /\.js$/,
-        loader: '@angular-devkit/build-optimizer/webpack-loader'
+        loader: '@angular-devkit/build-optimizer/webpack-loader',
         options: {
           sourceMap: false
         }