docs: Update changelog

Author: qqilihq

CHANGELOG.md

@@ -4,6 +4,10 @@ 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/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## [5.0.0] – 2026-01-24
+### Removed
+- Remove BGN from response typing (API does not longer provide this, as [Bulgaria joined euro area on 1 January 2026](https://www.ecb.europa.eu/press/pr/date/2025/html/ecb.pr250708~b9676a9fa8.en.html))
+
 ## [4.0.1] – 2025-10-09
 ### Fixed
 - Use https: URL for endpoints everywhere