Update CHANGELOG.md

CHANGELOG.md

@@ -5,7 +5,8 @@ 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).
 
-# [0.5.0] - 2023-09-20
+## [0.5.0] - 2023-09-20
+
 ### Added
 
 - `Peptidoform`: Added support for `iter()` and `len()` methods
@@ -40,13 +41,13 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - docs: Set newer `build>os` configuration for readthedocs.org
 - CI: Upgrade Github action versions
 
-# [0.4.1] - 2023-07-06
+## [0.4.1] - 2023-07-06
 
 ### Fixed
 
 - `PSMList`: Revert comparison operator change from v0.4.0 that results in broken `calculate_qvalues()` method (E711; Numpy array, not singleton)
 
-# [0.4.0] - 2023-07-06
+## [0.4.0] - 2023-07-06
 
 ### Added