docs: CHANGELOG update to v0.4.0

Author: tobbee

CHANGELOG.md

@@ -7,6 +7,10 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+- Nothing yet
+
+## [v0.4.0] 2025-03-11
+
 ### Added
 
 - EncodeWithSkip() to media playlist
@@ -96,7 +100,8 @@ The following changes are wrt to initial copy of [grafov/m3u8][grafov] files:
 
 - initial version of the repo
 
-[Unreleased]: https://github.com/Eyevinn/mp4ff/compare/v0.3.0...HEAD
+[Unreleased]: https://github.com/Eyevinn/mp4ff/compare/v0.4.0...HEAD
+[v0.4.0]: https://github.com/Eyevinn/mp4ff/compare/v0.3.0...v0.4.0
 [v0.3.0]: https://github.com/Eyevinn/mp4ff/compare/v0.2.0...v0.3.0
 [v0.2.0]: https://github.com/Eyevinn/mp4ff/compare/v0.1.0...v0.2.0
 [grafov]: https://github.com/grafov/m3u8