Added demo for kernel blur

dist/preview release/what's new.md

@@ -21,7 +21,7 @@
  - All deprecated functions and properties were removed ([deltakosh](https://github.com/deltakosh))
  - New build system based on workloads. [More info here](http://doc.babylonjs.com/generals/how_to_start#custom-builds) ([deltakosh](https://github.com/deltakosh))
  - New `Cell Shading` material added into `Materials Library` [Demo](http://www.babylonjs.com/Demos/CellShading/) ([Julien Moreau-Mathis](https://github.com/julien-moreau))
- - New kernel based blur. [Demo]( ([deltakosh](https://github.com/deltakosh))
+ - New kernel based blur. [Demo](https://www.babylonjs-playground.com/#FBH4J7#1) ([deltakosh](https://github.com/deltakosh))
  
 ### Updates
 - Added `ArcRotateCamera.panningInertia` to decouple inertia from panning inertia ([deltakosh](https://github.com/deltakosh))