Update changelog

Author: borkweb

CHANGELOG.md

@@ -4,8 +4,12 @@ All notable changes to this project will be documented in this file. This projec
 
 ## [unreleased] Unreleased
 
+## [1.0.0] 2022-08-17
+
 ### Added
 
 - Initial version
 - Documentation
 - Automated tests
+
+[1.0.0]: https://github.com/stellarwp/schema/releases/tag/1.0.0