updating version and changelog

Author: TensAndTwenties

CHANGELOG.md

@@ -5,7 +5,9 @@ All notable changes to this project 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).
 
-## [1.2.0] - unreleased
+## [1.2.1] - unreleased
+
+## [1.2.0] - 2024-12-02
 
 ### Changed