Add changelog to track important changes

RELEASE-NOTES.md

@@ -0,0 +1,54 @@
+[comment]: # (#################################################################)
+[comment]: # (Copyright (c) Lawrence Livermore National Security, LLC and)
+[comment]: # (other Smith Project Developers. See the top-level LICENSE file)
+[comment]: # (for details.)
+[comment]: #
+[comment]: # (SPDX-License-Identifier: (BSD-3-Clause))
+[comment]: # (#################################################################)
+
+
+# Smith Software Release Notes
+
+Notes describing significant changes in each Smith release are documented in this file.
+
+The format of this file is based on [Keep a Changelog](http://keepachangelog.com/en/1.0.0/).
+
+The Smith project release numbers follow [Semantic Versioning](http://semver.org/spec/v2.0.0.html).
+
+## [Unreleased] - Release date yyyy-mm-dd
+
+### Added
+
+- Added this release notes file to track changes in project
+
+### Removed
+
+### Deprecated
+
+### Changed
+
+### Fixed
+
+## [Version 0.1.0] - Release date 2026-04-28
+
+## Legend for sections
+
+###  Added
+- Use this section for new features
+
+###  Changed
+- Use this section for changes in existing functionality
+
+###  Deprecated
+- Use this section for soon-to-be removed features
+
+###  Removed
+- Use this section for now removed features
+
+###  Fixed
+- Use this section for any bug fixes
+
+###  Security
+- Use this section in case of vulnerabilities
+
+[Version 0.1.0]: https://github.com/llnl/smith/releases/tag/v0.1.0