fix changelog

Author: Pan-Qi

src/Portal/Portal/ChangeLog.md

@@ -18,7 +18,7 @@
         - Additional information about change #1
 -->
 ## Upcoming Release
-* Regenerate the module using the latest v4 generator to incorporate the new features added in the v4 generator.
+* Introduced various new features by upgrading code generator. Please see detail [here](https://github.com/Azure/azure-powershell/blob/main/documentation/Autorest-powershell-v4-new-features.md).
 
 ## Version 0.3.0
 * Updated Api Version to 2022-12-01-preview.