chore: adds CHANGELOG md template file

Author: hartmut-co-uk

CHANGELOG.md

@@ -0,0 +1,27 @@
+# Changelog
+All notable changes to this project will be documented in this file.
+
+The format is based on [Keep a Changelog](https://keepachangelog.com/),
+and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
+
+
+## Template [x.y.z](https://github.com/thriving-dev/java-library-template/releases/tag/x.y.z) (yyyy-mm-dd)
+[a.b.c...x.y.z](https://github.com/thriving-dev/java-library-template/compare/a.b.c...x.y.z)
+
+### Added
+- for new features
+
+### Changed
+- for changes in existing functionality
+
+### Deprecated
+- for soon-to-be removed features
+
+### Removed
+- for now removed features
+
+### Fixed
+- for any bug fixes
+
+### Security
+- in case of vulnerabilities