Release v5.8

Author: calixtus

CHANGELOG.md

@@ -7,7 +7,7 @@ In case, there is no issue present, the pull request implementing the feature is
 
 Note that this project **does not** adhere to [Semantic Versioning](http://semver.org/).
 
-## [Unreleased]
+## [5.8] - 2022-12-18
 
 ### Added
 
@@ -933,7 +933,7 @@ The changelog of JabRef 4.x is available at the [v4.3.1 tag](https://github.com/
 The changelog of JabRef 3.x is available at the [v3.8.2 tag](https://github.com/JabRef/jabref/blob/v3.8.2/CHANGELOG.md).
 The changelog of JabRef 2.11 and all previous versions is available as [text file in the v2.11.1 tag](https://github.com/JabRef/jabref/blob/v2.11.1/CHANGELOG).
 
-[Unreleased]: https://github.com/JabRef/jabref/compare/v5.7...HEAD
+[5.8]: https://github.com/JabRef/jabref/compare/v5.7...v5.8
 [5.7]: https://github.com/JabRef/jabref/compare/v5.6...v5.7
 [5.6]: https://github.com/JabRef/jabref/compare/v5.5...v5.6
 [5.5]: https://github.com/JabRef/jabref/compare/v5.4...v5.5