docs(readme): add a note about media query extraction (media-query-plugin) (#235)

Author: SassNinja

README.md

@@ -272,6 +272,11 @@ module.exports = {
 
 For long term caching use `filename: "[contenthash].css"`. Optionally add `[name]`.
 
+### Media Query Plugin
+
+If you'd like to extract the media queries from the extracted CSS (so mobile users don't need to load desktop specific CSS anymore) you should use the [media-query-plugin](https://github.com/SassNinja/media-query-plugin). It will take over the filename option of the mini-css-extract-plugin and recognize its generated CSS chunks.
+
+
 <h2 align="center">Maintainers</h2>
 
 <table>