Update CHANGELOG

Author: phinner

CHANGELOG.md

@@ -5,6 +5,16 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](http://keepachangelog.com/),
 and this project adheres to [Semantic Versioning](http://semver.org/).
 
+## v4.1.0-k.2.1.0 - 2025-01-09
+
+### Bugfixes
+
+- The mod descriptor file was named `plugin.json` instead of `mod.json`. It has been fixed.
+
+### Chores
+
+- Updated kotlin serialization to `1.8.0`.
+
 ## v4.0.1-k.2.1.0 - 2024-12-27
 
 ### Chores