Update readme.md

readme.md

@@ -12,12 +12,16 @@ Getting started? Play directly with the Babylon.js API via our [playground](http
 - https://cdn.babylonjs.com/babylon.max.js
 - https://cdn.babylonjs.com/babylon.worker.js
 
+Additional references can be found on https://cdn.babylonjs.com/xxx where xxx is the folder structure you can find in the /dist folder like https://cdn.babylonjs.com/gui/babylon.gui.min.js
+
 For preview release you can use the following ones:
 
 - https://preview.babylonjs.com/babylon.js
 - https://preview.babylonjs.com/babylon.max.js
 - https://preview.babylonjs.com/babylon.worker.js
 
+Additional references can be found on https://preview.babylonjs.com/xxx where xxx is the folder structure you can find in the /dist/preview release folder like https://preview.babylonjs.com/gui/babylon.gui.min.js
+
 ## Preview release
 
 **3.1-alpha** can be found [here](https://github.com/BabylonJS/Babylon.js/tree/master/dist/preview%20release).