Changelog update - v0.3.0 (#127)

Current pull request contains patched `CHANGELOG.md` file for the
`v0.3.0` version.

Co-authored-by: GitHub Action <[email protected]>

Author: github-actions[bot]

CHANGELOG.md

@@ -2,6 +2,8 @@
 
 ## Unreleased
 
+## 0.3.0 - 2025-06-10
+
 ### Added
 
 - support for Toolbox 2.6.3 with improved URI handling