docs: Add OAuth 2.1 and TOON Format documentation - Add comprehensive OAuth 2.1 Authentication guide - Quick start and setup instructions - OAuth scopes and access control - Configuration files (oauth-clients.json, oauth-secrets.json) - Client types (public vs confidential) - Docker deployment examples - Security best practices - Troubleshooting guide - Example configurations - Add TOON Format documentation - What is TOON (Text-Optimized Output Notation) - Benefits of enhanced formatting - Example outputs with before/after - Configuration and disabling - When to use vs disable TOON - Update Home.md - Add links to new OAuth 2.1 and TOON pages - Mark as NEW features - Update Security-Guide.md - Add AUTH_TYPE authentication modes section - Reference OAuth 2.1 documentation - Clarify Bearer token vs OAuth 2.1 vs no auth Closes #1 (OAuth 2.0 authentication support)