Update CHANGELOG.md

Author: cicirello

CHANGELOG.md

@@ -4,9 +4,10 @@ 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] - 2021-03-29
+## [Unreleased] - 2021-03-31
 
 ### Added
+* Added the `Permutation.Mechanic.set(Permutation, int[], int, int, int)` method.
 
 ### Changed