chore: prepare v0.20.0 (#133)

Signed-off-by: Max Inden <[email protected]>

Author: mxinden

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/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
-## [0.20.0] [unreleased]
+## [0.20.0]
 
 ### Added