release 8.1.0: update changelog (#2026)

* Update CHANGELOG

* Update grouping

* Update

* Apply suggestions from code review

Co-authored-by: Karl Heinz Struggl <kahest@users.noreply.github.com>

---------

Co-authored-by: Karl Heinz Struggl <kahest@users.noreply.github.com>

CHANGELOG.md

@@ -4,8 +4,9 @@
 
 ### Feature
 
-- Set snapshot to `true` when Sentry attaches a stacktrace ([#2000](https://github.com/getsentry/sentry-dart/pull/2000)) 
-  - This may change grouping
+- Set snapshot to `true` if stacktrace is not provided ([#2000](https://github.com/getsentry/sentry-dart/pull/2000))
+  - If the stacktrace is not provided, the Sentry SDK will fetch the current stacktrace via `StackTrace.current` and the snapshot will be set to `true` - **this may change the grouping behavior**
+  - `snapshot = true` means it's a synthetic exception, reflecting the current state of the thread rather than the stack trace of a real exception
 
 ### Fixes