Add ChatNow link and API usage section to README - Updated header section with ChatNow link pointing to ZenMux deployment - Added Try Online section with direct link to online experience - Added API Usage section with OpenAI-compatible client example - Enhanced Quickstart section with user-friendly access methods 🤖 Generated with [Claude Code](https://claude.ai/code) Co-Authored-By: Claude <noreply@anthropic.com>
