Update CHANGELOG for version 3.1.0

Author: mullerch

CHANGELOG.md

@@ -5,6 +5,13 @@ All notable changes to this project since will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## [3.1.0] - 2025-04-28
+
+### Added
+
+- Generate stringer implementations for all enum types
+- Add newest device properties and centralize HwAddress property
+
 ## [3.0.0] - 2025-01-24
 
 ### Fixed