add note in CHANGELOG file

Author: bluepal-prasanthi-moparthi

v2/CHANGELOG.md

@@ -9,6 +9,7 @@
 - Add missing endpoints from authentication to v2
 - Add missing endpoints from general-request-handling to v2
 - Add benchmark tests for v1 and v2 to compare performance
+- Add len() for Read methods
 
 ## [2.1.5](https://github.com/arangodb/go-driver/tree/v2.1.5) (2025-08-31)
 - Add tasks endpoints to v2