Add "Unreleased" section (and enable diffs also for older versions)

CHANGELOG.md

@@ -1,8 +1,11 @@
 # Changelog
+
 All notable changes to this project will be documented in this file.
 
 The format is based on [Keep a Changelog](https://keepachangelog.com/).
 
+## [Unreleased]
+
 ## [1.8] - 2023-11-26
 
 ### Added
@@ -69,7 +72,6 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/).
 - `hyperref` is loaded without options to make it more compatible with other packages like `authorarchive`
 - `hypcap` is only loaded if `hyperref` has been loaded before.
 
-
 ## [1.5] - 2019-04-04
 
 ### Added
@@ -157,12 +159,12 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/).
 First release of the revised files
 
 [Unreleased]: https://github.com/gi-ev/LNI/compare/v1.8...HEAD
-[1.8]: https://github.com/gi-ev/LNI/releases/tag/v1.8
-[1.7]: https://github.com/gi-ev/LNI/releases/tag/v1.7.0
-[1.6]: https://github.com/gi-ev/LNI/releases/tag/v1.6.0
-[1.5]: https://github.com/gi-ev/LNI/releases/tag/v1.5
-[1.4]: https://github.com/gi-ev/LNI/releases/tag/v1.4
-[1.3]: https://github.com/gi-ev/LNI/releases/tag/v1.3
-[1.2]: https://github.com/gi-ev/LNI/releases/tag/v1.2
-[1.1]: https://github.com/gi-ev/LNI/releases/tag/v1.1
+[1.8]: https://github.com/gi-ev/LNI/compare/v1.7...v1.8
+[1.7]: https://github.com/gi-ev/LNI/compare/v1.6...v1.7
+[1.6]: https://github.com/gi-ev/LNI/compare/v1.5...v1.6
+[1.5]: https://github.com/gi-ev/LNI/compare/v1.4...v1.5
+[1.4]: https://github.com/gi-ev/LNI/compare/v1.3...v1.4
+[1.3]: https://github.com/gi-ev/LNI/compare/v1.2...v1.3
+[1.2]: https://github.com/gi-ev/LNI/compare/v1.1...v1.2
+[1.1]: https://github.com/gi-ev/LNI/compare/v1.0...v1.1
 [1.0]: https://github.com/gi-ev/LNI/releases/tag/v1.0