[Search] Update changelog (#30328)

* [Search] Update changelog

Author: ShivangiReja

sdk/search/Azure.Search.Documents/CHANGELOG.md

@@ -4,6 +4,7 @@
 
 ### Features Added
 - Added support for [Lexical normalizers](https://docs.microsoft.com/azure/search/search-normalizers#normalizers) in `SimpleField` and `SearchableField`.
+- Added multi-cloud support via `SearchClientOptions.Audience` to allow users to select the Azure cloud where the resource is located ([#30306](https://github.com/Azure/azure-sdk-for-net/issues/30306)).
 
 ## 11.4.0-beta.8 (2022-07-07)