Release version 2.8.0 (#474)

* Release 2.8.0

* Fix code style!

Co-authored-by: markuspoerschke <markuspoerschke@users.noreply.github.com>
Co-authored-by: markuspoerschke-bot <markuspoerschke-bot@users.noreply.github.com>

CHANGELOG.md

@@ -7,6 +7,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+## [2.8.0] - 2022-12-22
+
 ### Added
 
 -   Support chaining of Calendar.setPublishedTTL() [#452](https://github.com/markuspoerschke/iCal/pull/452)
@@ -240,7 +242,8 @@ Please check the [upgrade guide](UPGRADE.md) on how to upgrade from version `0.*
 -   **Breaking Change:** Changed signature of the `Event::setOrganizer` method. Now there is is only one parameter that must be an instance of `Property\Organizer`.
 -   Updated install section in README.md [#54](https://github.com/markuspoerschke/iCal/pull/53)
 
-[unreleased]: https://github.com/markuspoerschke/iCal/compare/2.7.0...HEAD
+[unreleased]: https://github.com/markuspoerschke/iCal/compare/2.8.0...HEAD
+[2.8.0]: https://github.com/markuspoerschke/iCal/compare/2.7.0...2.8.0
 [2.7.0]: https://github.com/markuspoerschke/iCal/compare/2.6.0...2.7.0
 [2.6.0]: https://github.com/markuspoerschke/iCal/compare/2.5.1...2.6.0
 [2.5.1]: https://github.com/markuspoerschke/iCal/compare/2.5.0...2.5.1