docs: update CHANGELOG.md

Author: Pakisan

CHANGELOG.md

@@ -5,6 +5,12 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.1.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## [1.0.0-RC4] - 2025-04-30
+
+### Added
+
+- Support for XML/XSD-based schemas
+
 ## [1.0.0-RC3] - 2025-01-21
 
 ### Changed