Update what's new.md

Added OBJ loader in the what's new 2.2

dist/preview release - alpha/what's new.md

@@ -5,6 +5,7 @@
     - New rewored StandardMaterial.isReady for better memory usage and performance [deltakosh](https://github.com/deltakosh)
     - Revamping of FBX exporter. Now supports animations and bones [simonferquel](http://www.github.com/simonferquel), [deltakosh](https://github.com/deltakosh)
     - StandardMaterial.useGlossinessFromSpecularMapAlpha to use specular map alpha as glossiness level [deltakosh](https://github.com/deltakosh)
+    - OBJ loader. See [demo here](http://www.babylonjs-playground.com/#28YUR5) [Temechon](https://github.com/Temechon)
   - **Updates**
     - Added scene.getLensFlareSystemByName() [deltakosh](https://github.com/deltakosh)
     - Added LensFlareSystem.setEmitter() [deltakosh](https://github.com/deltakosh)