update changelog for v2.12 release

CHANGELOG.md

@@ -4,6 +4,10 @@ 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).
 
+## [2.12.0] - 2021-09-27
+### Added
+- Zooming feature (enable by setting markerArea.uiStyleSettings.zoomButtonVisible = true)
+
 ## [2.11.2] - 2021-08-26
 ### Fixed
 - CurveMarker wasn't scaled properly when resizing
@@ -271,6 +275,7 @@ of the whole page (and other events) are handled by the browser as expected).
 ### Added
 - Initial public release.
 
+[2.12.0]: https://github.com/ailon/markerjs2/releases/tag/v2.12.0
 [2.11.2]: https://github.com/ailon/markerjs2/releases/tag/v2.11.2
 [2.11.1]: https://github.com/ailon/markerjs2/releases/tag/v2.11.1
 [2.11.0]: https://github.com/ailon/markerjs2/releases/tag/v2.11.0