Removed unreleased section. (#5667)

Author: miguelalonsojr

com.unity.ml-agents/CHANGELOG.md

@@ -6,22 +6,6 @@ The format is based on [Keep a Changelog](http://keepachangelog.com/en/1.0.0/)
 and this project adheres to
 [Semantic Versioning](http://semver.org/spec/v2.0.0.html).
 
-## [Unreleased]
-### Major Changes
-#### com.unity.ml-agents / com.unity.ml-agents.extensions (C#)
-
-#### ml-agents / ml-agents-envs / gym-unity (Python)
-
-### Minor Changes
-#### com.unity.ml-agents / com.unity.ml-agents.extensions (C#)
-
-#### ml-agents / ml-agents-envs / gym-unity (Python)
-
-### Bug Fixes
-#### com.unity.ml-agents / com.unity.ml-agents.extensions (C#)
-
-#### ml-agents / ml-agents-envs / gym-unity (Python)
-
 ## [2.2.0] - 2022-01-14
 ### Major Changes