Update installation scripts and documentation

- Enhanced install.sh with better error handling and multi-shell support
- Updated configuration files (CLAUDE.md, MCP.md, RULES.md) to latest version
- Added comprehensive CONTRIBUTING.md guidelines
- Improved README.md formatting and clarity
- Fixed Commands_Cheat_Sheet.md formatting
- Updated .gitignore with better exclusions
- Minor LICENSE and CHANGELOG.md updates

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

.gitignore

@@ -11,13 +11,26 @@ logs/
 # System files
 .DS_Store
 Thumbs.db
+desktop.ini
+.Spotlight-V100
+.Trashes
 
 # IDE files
 .vscode/
 .idea/
 *.swp
 *.swo
+*~
+.project
+.settings/
 
 # Temporary files
 *.tmp
-*.temp
+*.temp
+*.bak
+*.backup
+*.old
+.cache/
+
+# Backup files from install script
+superclaude-backup.*