Update CHANGELOG.md

Author: keveleigh

org.mixedrealitytoolkit.input/CHANGELOG.md

@@ -8,6 +8,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.1.0/).
 
 * Added a project validation rule to ensure the Unity XR Hands subsystem is enabled in the OpenXR settings when the corresponding MRTK subsystem is enabled. [PR #973](https://github.com/MixedRealityToolkit/MixedRealityToolkit-Unity/pull/973)
 * Added support for Unity's com.unity.cloud.gltfast and com.unity.cloud.ktx packages when loading controller models. [PR #631](https://github.com/MixedRealityToolkit/MixedRealityToolkit-Unity/pull/631)
+* Added support for XR_MSFT_hand_tracking_mesh and XR_ANDROID_hand_mesh on compatible runtimes. [PR #993](https://github.com/MixedRealityToolkit/MixedRealityToolkit-Unity/pull/993)
 
 ### Fixed