Update what's new.md

Author: jbousquie

dist/preview release/what's new.md

@@ -32,6 +32,7 @@
     - New OnPickTrigger support for spritesManager ([deltakosh](https://github.com/deltakosh))
     - New SPS method `digest()` ([jerome](https://github.com/jbousquie))    
     - New SPS property `computeBoundingBox` ([jerome](https://github.com/jbousquie))  
+    - New SPS particle property `isVisible` ([jerome](https://github.com/jbousquie)) 
     - Added a new OnPickOut trigger fired when you release the pointer button outside of a mesh or sprite. ([deltakosh](https://github.com/deltakosh))
     - Added support for OnPointerOver and OnPointerOut for sprites. ([deltakosh](https://github.com/deltakosh))
     - Added an optional predicate on Node.getDescendants, Node.getChildren to filter out Nodes based on a callback execution. ([nockawa](https://github.com/nockawa))