Update CHANGELOG.md

Author: coskunaydinoglu

CHANGELOG.md

@@ -1,7 +1,7 @@
 ## Version 25.03.XX
 Enterprise Fixes:
 - [journeys] Fix for performance issues when huge number of journey instances created
-
+- [journeys] Fix for content shown event handling
 Fixes:
 - [server-stats] Fix breakdown event calculation
 - [server-stats] Add new events to breakdown