Update CHANGELOG.md (#4036)

CHANGELOG.md

@@ -5,7 +5,7 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](http://keepachangelog.com/en/1.0.0/)
 and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.html).
 
-## Unreleased
+## [3.0.0-dev1]
 
 ### Added
 
@@ -1542,6 +1542,7 @@ Some discrepancies with the TR remain, and are being tracked under https://githu
 
 Initial pre-release
 
+[3.0.0-dev1]: https://github.com/microsoft/CCF/releases/tag/ccf-3.0.0-dev1
 [3.0.0-dev0]: https://github.com/microsoft/CCF/releases/tag/ccf-3.0.0-dev0
 [2.0.0]: https://github.com/microsoft/CCF/releases/tag/ccf-2.0.0
 [2.0.0-rc9]: https://github.com/microsoft/CCF/releases/tag/ccf-2.0.0-rc9