docs: Add FAQ section for common questions

[meichuanyi]

Summary

Add comprehensive FAQ section covering AgentKit multi-agent framework:

• What is AgentKit? (TypeScript framework for multi-agent networks)
• Core Concepts (Agents/Networks/State/Routers/Tracing)
• Installation and Quick Start examples
• Requirements (Node.js/Model providers/MCP servers)
• Key Features (Deterministic routing/MCP integration/Fault tolerance)
• License and Help resources

Changes

• Add ~70 line FAQ section with structured tables
• Include npm install commands and TypeScript code example
• Add MCP server integration guidance
• Link to documentation and community channels

Checklist

• Documentation improvement
• No code changes
• Follows existing README format

[changeset-bot]

⚠️ No Changeset found

Latest commit: f050751

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