Add changelog for release checklist foundation release

Author: simaba

CHANGELOG.md

@@ -0,0 +1,28 @@
+# Changelog
+
+All notable changes to this project will be documented in this file.
+
+## [0.1.0] — Foundation release
+
+### Added
+
+- Packaged `release-checklist` CLI for validating YAML-based AI release-readiness configurations.
+- Risk-tiered gate requirements for low, medium, and high risk systems.
+- Example configurations for medium-risk and high-risk releases.
+- Template generation through `release-checklist init`.
+- Text, JSON, and Markdown report rendering.
+- CI workflow covering supported Python versions and packaged CLI behavior.
+- Tests for validator behavior, required gates, metadata, strict mode, and invalid YAML.
+
+### Improved
+
+- Validator enforces required top-level sections and metadata fields.
+- Validator enforces allow-listed environment, industry, and risk-tier values.
+- Validator checks mapping/object shape for known structural sections.
+- Validator enforces boolean types for known gates.
+- Validator enforces bounded numeric values for known threshold fields.
+- Metadata is excluded from gate accounting so strict mode focuses on actual release-readiness gates.
+
+### Notes
+
+This is a lightweight release-readiness validator, not a full policy engine. It is designed to provide repeatable local and CI-friendly checks that can support broader release governance workflows.