docs: Add comprehensive CHANGELOG.md with semantic versioning

- Implement industry-standard changelog format based on Keep a Changelog
- Initialize with version 0.1.0 documenting initial project setup
- Include semantic versioning guidelines and contribution instructions
- Document all current features and technical architecture
- Establish versioning workflow for future development

Follows SemVer specification and changelog best practices

Author: KCoderVA

CHANGELOG.md

@@ -0,0 +1,107 @@
+# Changelog
+
+All notable changes to this project will be documented in this file.
+
+The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
+and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
+
+## [Unreleased]
+
+### Added
+### Changed
+### Deprecated
+### Removed
+### Fixed
+### Security
+
+## [0.1.0] - 2025-07-17
+
+### Added
+- Initial project structure with modular JavaScript architecture
+- Unified dashboard with dynamic environment detection (`index.html`)
+- Offline-specific HTML dashboard (`Commit_Productivity_Dashboard.html`)
+- Core functionality modules:
+  - Git analyzer for local repository processing
+  - GitHub API integration for remote repository analysis
+  - Data processor for commit log analysis and productivity metrics
+- User interface components:
+  - Dashboard with responsive design
+  - Chart visualization system
+  - Repository selection interface
+- Utility modules:
+  - File handling for local Git repository access
+  - Helper functions for data manipulation
+- Configuration system:
+  - Offline configuration for local analysis
+  - Online configuration for GitHub Pages deployment
+- Comprehensive documentation:
+  - User guide with setup instructions
+  - API documentation for developers
+  - README with project overview
+- Testing framework:
+  - Unit test structure for core modules
+  - Integration test setup for dashboard workflow
+- Development environment:
+  - VS Code workspace configuration
+  - Git repository with proper `.gitignore`
+  - Semantic versioning implementation
+- CSS styling system:
+  - Main stylesheet for core styling
+  - Dashboard-specific styles
+  - Responsive design for mobile compatibility
+
+### Technical Details
+- **Architecture**: Modular JavaScript (ES6+) with separation of concerns
+- **Styling**: CSS3 with responsive design principles
+- **Version Control**: Git repository initialized with comprehensive `.gitignore`
+- **Documentation**: Markdown-based documentation following best practices
+- **Testing**: Structured testing approach with unit and integration test separation
+- **Configuration**: Environment-specific configurations for deployment flexibility
+
+---
+
+## Semantic Versioning Guidelines
+
+This project follows [Semantic Versioning](https://semver.org/) (SemVer):
+
+- **MAJOR** version (X.y.z) - Incompatible API changes
+- **MINOR** version (x.Y.z) - New functionality in a backwards compatible manner
+- **PATCH** version (x.y.Z) - Backwards compatible bug fixes
+
+### Version History Format
+
+Each version entry includes:
+- **Added** - New features
+- **Changed** - Changes in existing functionality
+- **Deprecated** - Soon-to-be removed features
+- **Removed** - Now removed features
+- **Fixed** - Bug fixes
+- **Security** - Vulnerability fixes
+
+### Release Links
+[Unreleased]: https://github.com/username/commit-log-productivity-dashboard/compare/v0.1.0...HEAD
+[0.1.0]: https://github.com/username/commit-log-productivity-dashboard/releases/tag/v0.1.0
+
+---
+
+## Contributing to the Changelog
+
+When making changes:
+
+1. **Always** update the `[Unreleased]` section first
+2. Use proper categorization (Added, Changed, Fixed, etc.)
+3. Write clear, concise descriptions
+4. Include technical details when relevant
+5. Reference issue numbers when applicable
+6. Move items from `[Unreleased]` to a new version section when releasing
+
+### Example Entry Format
+```markdown
+### Added
+- New commit analysis algorithm for better productivity metrics (#123)
+- Support for GitLab repositories in addition to GitHub (#145)
+
+### Fixed
+- Fixed timezone handling in commit timestamp analysis (#134)
+- Resolved memory leak in large repository processing (#156)
+```