add: note about next-gen SDK

Added a note about the next-generation SDK and its benefits.

Author: wilhelmer

README.md

@@ -1,5 +1,10 @@
 # Talon.One Java SDK
 
+> [!NOTE]
+The next-generation version of this SDK is available [here](https://github.com/talon-one/talon-one-java-sdk).
+The new SDK offers significant improvements, including immediate feature parity with the latest Talon.One
+product releases, as well as enhanced security and reliability.
+
 This SDK supports all of the operations of Talon.One's Integration API and Management API.
 
 If you use Maven, we also host [Maven Artifacts](https://github.com/talon-one/maven-artefacts).