Add version to changelog

Author: object-Object

CHANGELOG.md

@@ -4,7 +4,7 @@ All notable changes to this project will be documented in this file.
 
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.1.0/) and [Pydantic's HISTORY.md](https://github.com/pydantic/pydantic/blob/main/HISTORY.md), and this project *mostly* adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
-## [UNRELEASED]
+## 0.2.1+1.20.1
 
 ### Changed