Add a CHANGELOG file

CHANGELOG.md

@@ -0,0 +1,20 @@
+# 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).
+
+## [1.1.0] - 2020-11-27
+
+- Add `isDecorated` method on `SymfonyOutput` class and `Output` interface.
+- Fix missing `strict_types` on `Error` class
+- Add `AnsiEscapeSequences` to help with some often used sequences
+
+## [1.0.0] - 2020-11-26
+
+- Initial version with support for `ErrorFormatter` classes from phpstan and more classes
+- Fixed imported tests
+- Added GitHub actions
+- Added phpstan
+- Removed some useless imported code
+- Made the imported source code compatible with PHP 7.1