Update CHANGELOG.md

[ci skip]

Author: williamdes

CHANGELOG.md

@@ -6,6 +6,8 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
 
 ## [Unreleased] - YYYY-MM-DD
 
+## [5.2.1] - 2023-02-08
+
 - Move docker-compose test files into a folder
 - Fix the section about E2E tests in `README.md`
 - Support docker secrets from file for `PMA_USER` (#372)