update changelog(#13)

Author: TheGupta2012

CHANGELOG.md

@@ -31,4 +31,5 @@ Types of changes:
 ### Added
 - Setup basic project/repo template ([#1](https://github.com/qBraid/pyqasm/pull/1))
 - Configured PyPI workflows ([#2](https://github.com/qBraid/pyqasm/pull/2))
-- Add initial implementation ([#3](https://github.com/qBraid/pyqasm/pull/3))
+- Add initial implementation ([#3](https://github.com/qBraid/pyqasm/pull/3))
+- Added test workflows and contribution templates ([#6](https://github.com/qBraid/pyqasm/pull/6))