Update CHANGELOG

Author: cable8mm

CHANGELOG.md

@@ -1 +1,13 @@
 # Release Notes
+
+## v1.0.0 - 2024-03-01
+
+### What's Changed
+
+* Remove composer.lock to test various versions by [@cable8mm](https://github.com/cable8mm) in https://github.com/cable8mm/array-flatten/pull/1
+
+### New Contributors
+
+* [@cable8mm](https://github.com/cable8mm) made their first contribution in https://github.com/cable8mm/array-flatten/pull/1
+
+**Full Changelog**: https://github.com/cable8mm/array-flatten/commits/v1.0.0