changelog note on grouping (#1684)

Author: bruno-garcia

CHANGELOG.md

@@ -4,8 +4,9 @@
 
 ### Fixes
 
-- Flatten AggregateException ([#1672](https://github.com/getsentry/sentry-dotnet/pull/1672))
 - Improve timestamp precision of transactions and spans ([#1680](https://github.com/getsentry/sentry-dotnet/pull/1680))
+- Flatten AggregateException ([#1672](https://github.com/getsentry/sentry-dotnet/pull/1672))
+  - NOTE: This can affect grouping. You can keep the original behavior by setting the option `KeepAggregateException` to `true`.  
 
 ### Features