Update CHANGELOG.md

Author: adriangl

CHANGELOG.md

@@ -174,7 +174,8 @@ state (`success` or `failure`)
 ### Added
 - Initial architecture release.
 
-[Unreleased]: https://github.com/hyperdevs-team/mini-kotlin/compare/3.0.0...HEAD
+[Unreleased]: https://github.com/hyperdevs-team/mini-kotlin/compare/3.1.0...HEAD
+[3.1.0]: https://github.com/hyperdevs-team/mini-kotlin/compare/3.0.0...3.1.0
 [3.0.0]: https://github.com/hyperdevs-team/mini-kotlin/compare/2.0.0...3.0.0
 [2.0.0]: https://github.com/hyperdevs-team/mini-kotlin/compare/1.4.0...2.0.0
 [1.4.0]: https://github.com/hyperdevs-team/mini-kotlin/compare/1.3.3...1.4.0