Punctuation and consistency pass on 'what's new.md' for 4.0.
Punctuation and consistency pass on 'what's new.md' for 4.0.

BabylonJS/Babylon.js,RaananW/Babylon.js,Kesshi/Babylon.js,jbousquie/Babylon.js,jbousquie/Babylon.js,RaananW/Babylon.js,NicolasBuecher/Babylon.js,NicolasBuecher/Babylon.js,sebavan/Babylon.js,BabylonJS/Babylon.js,Kesshi/Babylon.js,sebavan/Babylon.js,sebavan/Babylon.js,jbousquie/Babylon.js,BabylonJS/Babylon.js,RaananW/Babylon.js,Kesshi/Babylon.js,NicolasBuecher/Babylon.js