update changelog for release v0.2.4-alpha [no ci]

CHANGELOG.md

@@ -4,6 +4,8 @@ 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/).
 
 ## [Unreleased]
+
+## [0.2.4-alpha] - 2021-11-13
 ### Changed
 - Upgrade to dotnet 6
 - Use `scale_cuda` instead of `scale_npp` for NVIDIA scaling in all cases
@@ -788,7 +790,8 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
 - Initial release to facilitate testing outside of Docker.
 
 
-[Unreleased]: https://github.com/jasongdove/ErsatzTV/compare/v0.2.3-alpha...HEAD
+[Unreleased]: https://github.com/jasongdove/ErsatzTV/compare/v0.2.4-alpha...HEAD
+[0.2.4-alpha]: https://github.com/jasongdove/ErsatzTV/compare/v0.2.3-alpha...v0.2.4-alpha
 [0.2.3-alpha]: https://github.com/jasongdove/ErsatzTV/compare/v0.2.2-alpha...v0.2.3-alpha
 [0.2.2-alpha]: https://github.com/jasongdove/ErsatzTV/compare/v0.2.1-alpha...v0.2.2-alpha
 [0.2.1-alpha]: https://github.com/jasongdove/ErsatzTV/compare/v0.2.0-alpha...v0.2.1-alpha