Mention pytest 7 support

Author: jerry-git

CHANGELOG.md

@@ -4,6 +4,8 @@ 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).
 
 ## [Unreleased]
+### Added
+- Support for pytest 7.x, see https://github.com/jerry-git/pytest-split/pull/47
 
 ## [0.6.0] - 2022-01-10
 ### Added