Add default preload to readme file

Author: Wietse de Vries

README.md

@@ -357,6 +357,13 @@ const miniCssExtractPlugin = new MiniCssExtractPlugin({
 
 For long term caching use `filename: "[contenthash].css"`. Optionally add `[name]`.
 
+#### rel="preload" support
+
+ On browsers that support `<link rel="preload" as="style">`, then CSS links will be preloaded by default.
+This is both to improve page load performance, and addresess Chrome Lighthouse SEO performance audits requiring the use of rel="preload" with asynchronous chunks.
+
+ -[Lighthouse article](https://developers.google.com/web/tools/lighthouse/audits/preload)
+
 ### Remove Order Warnings
 
 For projects where css ordering has been mitigated through consistent use of scoping or naming conventions, the css order warnings can be disabled by setting the ignoreOrder flag to true for the plugin.