what's new update

dist/preview release/what's new.md

@@ -29,6 +29,7 @@
  - New blur mode for mirrors. [Demo](https://www.babylonjs-playground.com/#9I6NX1) ([deltakosh](https://github.com/deltakosh)) 
 
 ### Updates
+- New automatic creation mode for skybox. [Doc here](http://doc.babylonjs.com/tutorials/environment#automatic-creation) ([deltakosh](https://github.com/deltakosh))
 - New way to force compilation of materials. [Doc here](http://doc.babylonjs.com/tutorials/How_materials_work) ([deltakosh](https://github.com/deltakosh))
 - Added a Physics tab to the inspector ([abow](https://github.com/abow))
 - New Debug.PhysicsViewer class for viewing PhysicsImpostors. [Demo](http://www.babylonjs-playground.com/#CA51CM#2) ([abow](https://github.com/abow))