Update what's new.md

what's new.md

@@ -147,6 +147,7 @@
 - Added support for custom loader extensions ([bghgary](http://www.github.com/bghgary))
 - Added support for validating assets using [glTF-Validator](https://github.com/KhronosGroup/glTF-Validator) ([bghgary](http://www.github.com/bghgary))
 - Added automatically renormalizes skinweights when loading geometry. Calls core mesh functions to do this ([Bolloxim](https://github.com/Bolloxim))
+- Added support for morph target names via `mesh.extras.targetNames` ([zeux](https://github.com/zeux))
 
 ### glTF Serializer
 - Added support for exporting the scale, rotation and offset texture properties ([kcoley](http://www.github.com/kcoley))