Update Changelog for release

Author: tomtrafford

CHANGELOG.rst

@@ -3,7 +3,7 @@ Change Log
 All notable changes to this project will be documented in this file.
 This project adheres to `Semantic Versioning <http://semver.org/>`_ after 2-1.
 
-Unreleased
+`5.3`_ - 2022-03-18
 ----------
 
 Changed:
@@ -756,6 +756,7 @@ Added:
 
 - Initial release with hello world and websocket comms
 
+.. _5.3: https://github.com/dls-controls/pymalcolm/compare/5.2...5.3
 .. _5.2: https://github.com/dls-controls/pymalcolm/compare/5.1...5.2
 .. _5.1: https://github.com/dls-controls/pymalcolm/compare/5.0...5.1
 .. _5.0: https://github.com/dls-controls/pymalcolm/compare/4.6...5.0