prepare changelog for release (from GitHub Actions)

Author: CCDL-Bot

CHANGELOG.md

@@ -4,6 +4,7 @@ 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/).
 
 ## [Unreleased]
+## [1.4.0] 2024-02-23
 
 ### Added
 - Added proper support for the event steps `SHOW_MODAL_CHOICE` and `SET_MSG_EXPRESSION`.