Add changelog

Author: e1himself

CHANGELOG.md

@@ -0,0 +1,10 @@
+# Changelog
+
+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).
+
+## [1.0.0] - 2021-02-24
+### Added
+- Initial implementation.

README.md

@@ -43,6 +43,11 @@ $container->set('config', $config);
 $logger = $container->get('logger');
 ```
 
+## Changelog
+
+All notable changes to this project will be documented in the [CHANGELOG][./CHANGELOG.md] file.
+
+
 ## Credits
 
 - Implemented by [Ivan Voskoboinyk][3]