Update CHANGELOG.md for next release

Author: charphi

CHANGELOG.md

@@ -7,8 +7,10 @@ to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
 ## [Unreleased]
 
+## [3.0.0] - 2023-06-14
+
 This is the **initial release** of SDMX extensions for JDemetra+ v3.  
 [JDemetra+ v3.0.2 or later](https://github.com/jdemetra/jdplus-main) version is required to run it.
 
-
-[Unreleased]: https://github.com/nbbrd/jdplus-sdmx/compare/...HEAD
+[Unreleased]: https://github.com/nbbrd/jdplus-sdmx/compare/v3.0.0...HEAD
+[3.0.0]: https://github.com/nbbrd/jdplus-sdmx/releases/tag/v3.0.0