docs: prepare changelog for release 5.0.0-rc.2

Author: Birrer, Iwan

docs/changelog.md

@@ -6,16 +6,12 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.1.0/).
 
 ## Upcoming
 
-### Added
+## 5.0.0-rc.2 - 2025-08-28
 
 ### Fixed
 
 - `six-timepicker`: fixed issue with value getting cleared while typing
 
-### Removed
-
-### Changed
-
 ## 5.0.0-rc.1 - 2025-07-10
 
 ### Added