Update CHANGELOG.md

Author: vearutop

CHANGELOG.md

@@ -4,6 +4,11 @@ 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).
 
+## [0.12.40] - 2022-08-17
+
+### Fixed
+- Handling of unintialized typed properties, [#147](https://github.com/swaggest/php-json-schema/pull/147), [bruceoutdoors](https://github.com/bruceoutdoors).
+
 ## [0.12.39] - 2021-10-16
 
 ### Added
@@ -111,6 +116,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ### Changed
 - Export `null` value instead of skipping it for properties having `null` type.
 
+[0.12.40]: https://github.com/swaggest/php-json-schema/compare/v0.12.39...v0.12.40
 [0.12.39]: https://github.com/swaggest/php-json-schema/compare/v0.12.38...v0.12.39
 [0.12.38]: https://github.com/swaggest/php-json-schema/compare/v0.12.37...v0.12.38
 [0.12.37]: https://github.com/swaggest/php-json-schema/compare/v0.12.36...v0.12.37