Update whatsnew.md (#115)

Author: AdamRJensen

docs/source/whatsnew.md

@@ -4,13 +4,5 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
-## [0.1.0] - 2025-04-15
-
-### Added
-- Bullet one (see PR#1)
-
-### Changed
-
-### Testing
-
-### Requirements
+## [1.0.0] - 2025-09-22
+First stable release.