added dof demo

dist/preview release/what's new.md

@@ -14,7 +14,7 @@
 - Added [VideoDome](http://doc.babylonjs.com/how_to/360videodome) class to easily support 360 videos ([DavidHGillen](https://github.com/DavidHGillen))
 - Added [GlowLayer](https://doc.babylonjs.com/how_to/glow_layer) to easily support glow from emissive materials ([sebavan](https://github.com/sebavan))
 - New [AssetContainer](http://doc.babylonjs.com/how_to/how_to_use_assetcontainer) Class and loading methods ([trevordev](https://github.com/trevordev))
-- Added depth of field, sharpening, MSAA, chromatic aberration and grain effect to the default pipeline ([trevordev](https://github.com/trevordev))
+- Added [depth of field](https://www.babylonjs-playground.com/frame.html#8F5HYV#5), sharpening, MSAA, chromatic aberration and grain effect to the default pipeline ([trevordev](https://github.com/trevordev))
 - Added [particle system SubEmitters](http://doc.babylonjs.com/babylon101/particles#sub-emitters) which will spawn new particle systems when particles dies ([IbraheemOsama](https://github.com/IbraheemOsama))
 - New [particle system emitter shapes](http://doc.babylonjs.com/babylon101/particles#particles-shapes): cone and sphere ([IbraheemOsama](https://github.com/IbraheemOsama))
 - New [Babylon.js](http://doc.babylonjs.com/resources/maya) and [glTF](http://doc.babylonjs.com/resources/maya_to_gltf) exporter for Autodesk Maya ([Noalak](https://github.com/Noalak))