chore: update changelog for 0.2.0

Author: paolobrasolin

CHANGELOG.md

@@ -7,6 +7,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+## [0.2.0] - 2023-06-12
+
 ### Added
 
 - Make box ports count configurable.
@@ -17,5 +19,6 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 - Initial version.
 
-[unreleased]: https://github.com/paolobrasolin/string-diagrams/compare/v0.1.0...HEAD
+[unreleased]: https://github.com/paolobrasolin/string-diagrams/compare/v0.2.0...HEAD
+[0.2.0]: https://github.com/paolobrasolin/string-diagrams/compare/v0.1.0...v0.2.0
 [0.1.0]: https://github.com/paolobrasolin/string-diagrams/releases/tag/v0.1.0