Merge pull request #3751 from JeanPhilippeKernel/master

update what's new.md

dist/preview release/what's new.md

@@ -68,6 +68,7 @@
 - Ability to set a mesh to customize the webVR gaze tracker ([trevordev](https://github.com/trevordev))
 - Added promise-based async functions for initWebVRAsync and useStandingMatrixAsync ([trevordev](https://github.com/trevordev))
 - Add stroke (outline) options on GUI text control ([SvenFrankson](https://github.com/SvenFrankson))
+- Add isThumbClamped option on GUI slider control ([JeanPhilippeKernel](https://github.com/JeanPhilippeKernel))
 - Add floating point texture support for RenderTargetCubeTexture ([PeapBoy](https://github.com/NicolasBuecher))
 - Support for mutli-touch when interacting with multiple gui elements simultaneously ([trevordev](https://github.com/trevordev))
 - Added Draco mesh compression support to glTF 2.0 loader. ([bghgary](https://github.com/bghgary))