Add detailed changelog to README.md

- Add v2.0.0 changelog with all new features and improvements
- Include historical entries for v1.2.0 and v1.0.0
- Format changelog with categories (Major, New, Improved, Fixed)
- Add release dates for each version

🤖 Generated with [Claude Code](https://claude.ai/code)
Co-Authored-By: Claude <noreply@anthropic.com>

README.md

@@ -2,6 +2,32 @@
 
 A comprehensive web-based tool to automate and manage your Transmission torrent downloads with RSS feed integration, intelligent media organization, and enhanced security features. Now with automatic updates and easy installation!
 
+## Changelog
+
+### v2.0.0 (2025-03-05)
+- **Major**: Completely redesigned installation system using git
+- **New**: One-click update feature with version checking
+- **New**: Automatic Transmission detection and installation
+- **New**: System status dashboard with update notifications
+- **New**: About page with developer information
+- **Improved**: Better error handling for Transmission connection
+- **Fixed**: Various UI bugs and responsiveness issues
+
+### v1.2.0 (2025-02-15)
+- **New**: Enhanced media organization with better content detection
+- **New**: Improved post-processor with configurable filtering
+- **Improved**: Transmission client integration with better error handling
+- **Improved**: UI enhancements for better usability
+- **Fixed**: RSS feed parsing issues
+- **Fixed**: Authentication problems in certain configurations
+
+### v1.0.0 (2025-01-10)
+- **Initial Release**: Basic functionality for RSS feed monitoring
+- **New**: Integration with Transmission BitTorrent client
+- **New**: Web interface for managing torrents and feeds
+- **New**: Post-processing capability for downloaded content
+- **New**: Basic content categorization by media type
+
 ## Features
 
 - 🔄 **RSS Feed Integration**: Automatically download torrents from RSS feeds with customizable filters