Rephrase dev/prod dynamic adjustments to the config

Author: non25

README.md

@@ -65,7 +65,8 @@ A better option is to extract the CSS into a separate file. Using the `emitCss`
 
 ```javascript
   const MiniCssExtractPlugin = require('mini-css-extract-plugin');
-  const dev = mode == 'development';
+  const mode = process.env.NODE_ENV || 'development';
+  const prod = mode === 'production';
   ...
   module: {
     rules: [
@@ -83,7 +84,7 @@ A better option is to extract the CSS into a separate file. Using the `emitCss`
       {
         test: /\.css$/,
         use: [
-          dev ? 'style-loader' : MiniCssExtractPlugin.loader,
+          prod ? MiniCssExtractPlugin.loader :'style-loader',
           {
             loader: 'css-loader',
             options: {
@@ -103,7 +104,9 @@ A better option is to extract the CSS into a separate file. Using the `emitCss`
   ...
 ```
 
-Note that the configuration shown above switches off `MiniCssExtractPlugin` in development mode in favour of using CSS javascript injection. This is recommended by `MiniCssExtractPlugin` because it does not support hot reloading. `dev` is some boolean flag indicating that the build is development.
+Note that the configuration shown above switches off `MiniCssExtractPlugin` in development mode in favour of using CSS javascript injection. This is recommended by `MiniCssExtractPlugin` because it does not support hot reloading.
+
+`prod` indicates, that `NODE_ENV=production` has been set from `package.json` or manually (`NODE_ENV=production npx webpack`) for production builds. We can rely on that to make dynamic adjustments to the config.
 
 Additionally, if you're using multiple entrypoints, you may wish to change `new MiniCssExtractPlugin('styles.css')` for `new MiniCssExtractPlugin('[name].css')` to generate one CSS file per entrypoint.