docs: add contributing guidelines

Author: netshdev

CONTRIBUTING.md

@@ -0,0 +1,29 @@
+# Contributing to Agentic Code Standards
+
+## Updating the Changelog
+
+When submitting a pull request, please update `CHANGELOG.md` under the `[Unreleased]` section.
+
+### Types of Changes
+
+- `Added` for new features
+- `Changed` for changes in existing functionality
+- `Deprecated` for soon-to-be removed features
+- `Removed` for now removed features
+- `Fixed` for any bug fixes
+- `Security` for vulnerability fixes
+
+### Example
+
+```markdown
+## [Unreleased]
+
+### Added
+
+- Python coding standards
+- Vue.js component guidelines
+
+### Fixed
+
+- Typo in accessibility documentation
+```