Updating CHANGELOG for 5.0.0.

Author: cyrilverloop

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).
 
-## [Unreleased]
+## [5.0.0] - 2024-05-23
 ### Changed
 - Configurations, inputs, outputs and default codes are now in a separate project.
 - Default codes and tests are now generated in the `Easy`, `Medium`, `Hard` and `Expert` sub-directories