Update CHANGELOG.md

Introduce new unrelease section

CHANGELOG.md

@@ -6,6 +6,12 @@ For each version important additions, changes and removals are listed here.
 The format is inspired from [Keep a Changelog](http://keepachangelog.com/en/1.0.0/)
 and the versioning aims to respect [Semantic Versioning](http://semver.org/spec/v2.0.0.html).
 
+## [v0.XX.X] unreleased - 2024-XX-XX
+### Added
+### Changed
+- Fix usercff workflow [#545](https://github.com/OpenEnergyPlatform/open-MaStR/issues/544)
+### Removed
+
 ## [v0.14.4] Release for the Journal of Open Source Software JOSS - 2024-06-07
 ### Added
 - Extend documentation section `getting started` based on the JOSS Review [#523](https://github.com/OpenEnergyPlatform/open-MaStR/pull/523)