Update what's new

dist/preview release/what's new.md

@@ -9,3 +9,5 @@
 - Fix issue with the Promise polyfill where a return value was expected from resolve() ([Deltakosh](https://github.com/deltakosh))
 
 ## Breaking changes
+
+- Use both `mesh.visibility` and `material.alpha` values to compute the global alpha value used by the soft transparent shadow rendering code. Formerly was only using `mesh.visibility` ([Popov72](https://github.com/Popov72))