docs: add FAQ section

[meichuanyi]

Summary

This PR adds a comprehensive FAQ section to the README.md to help developers quickly understand TypedAI and find answers to common questions.

FAQ Coverage

The FAQ section covers:

• Platform Concept: What is TypedAI and its TypeScript-first approach
• Comparison: How TypedAI compares to LangChain and CrewAI
• Quick Start: Installation and CLI usage examples
• LLM Providers: Supported providers (OpenAI, Anthropic, Gemini, Groq, Fireworks, Together.ai, DeepSeek, Ollama, Cerebras, SambaNova, OpenRouter, X.ai)
• Autonomous Agents: Self-Discover reasoning, memory, hierarchical decomposition, sandboxed execution, schema generation
• Software Developer Agents: Code Editing Agent, Software Engineer Agent, Code Review Agent, Query Agent, Index Agent
• Custom Functions: @func decorator for automatic schema generation
• Integrations/Tools: Filesystem, Jira, Slack, Perplexity, Google Cloud, GitLab, GitHub
• Deployment Options: Local, CLI, Web UI, Cloud Run, Enterprise SSO
• Python Ecosystem: Leveraging Python AI ecosystem through script execution
• Observability: OpenTelemetry-based tracing, metrics, logs
• Multi-Agent Reasoning: extend-reasoning implementations
• Contributing: Issues, PRs, Discussions links
• Resources: Documentation, setup, autonomous agents, software engineer, integrations, roadmap links

Checklist

• Documentation update only (no code changes)
• FAQ content based on existing README information
• All links verified
• TypeScript-first perspective maintained