Added improvements to changelog

Author: grogy

CHANGELOG.md

@@ -23,6 +23,8 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
 - PHPUnit: make the tests platform independent [#15](https://github.com/php-parallel-lint/PHP-Console-Highlighter/pull/15) from [@jrfnl](https://github.com/jrfnl).
 - PHPUnit: use annotations for fixtures / cross-version compat up to PHPUnit 9.x [#15](https://github.com/php-parallel-lint/PHP-Console-Highlighter/pull/15) from [@jrfnl](https://github.com/jrfnl).
 - PHPUnit: improve configuration [#21](https://github.com/php-parallel-lint/PHP-Console-Highlighter/pull/21) from [@jrfnl](https://github.com/jrfnl).
+- PHP 8.0: handle changed tokenization of namespaced names [#19](https://github.com/php-parallel-lint/PHP-Console-Highlighter/pull/19) from [@jrfnl](https://github.com/jrfnl).
+- PHPCS: various improvements [#20](https://github.com/php-parallel-lint/PHP-Console-Highlighter/pull/20) from [@jrfnl](https://github.com/jrfnl).
 
 ## [0.5] - 2020-05-13