docs: add FAQ section

[meichuanyi]

Summary

This PR adds a comprehensive FAQ section to the README.md, addressing common questions users may have about PentestAgent.

Changes

Added ❓ FAQ section covering:

• Platform Overview: What is PentestAgent (AI-powered pentest tool with LLM guidance)
• Comparison: How PentestAgent differs from traditional pentest tools (AI-guided vs manual)
• Installation: Two options (Clone + setup, Docker recommended)
• LLM Providers: Anthropic Claude (recommended), OpenAI GPT-4, LiteLLM-supported providers
• Docker Usage: Base image vs Kali image (metasploit, sqlmap, hydra)
• MCP Support: Model Context Protocol integration
• RAG System: Shadow graph and knowledge retrieval
• Rewind Feature: Undo previous actions, revert to earlier states
• Testing: pytest with coverage
• Playbooks: Pre-defined attack sequences
• Local Models: Ollama, LM Studio, vLLM
• Security: Legal notice and safety considerations
• Custom Tools: How to add tools in tools/ directory
• Help Resources: GitHub README, Issues, Community

Motivation

PentestAgent README lacks a FAQ section, which is valuable for:

• New users to understand the platform quickly
• Answering common questions about AI-powered pentesting
• Explaining legal and security considerations
• Improving project accessibility and safety awareness

Checklist

• FAQ content is accurate and helpful
• Markdown formatting is correct
• Legal notice is clear and prominent
• Questions reflect real user needs

Related

Addresses a common documentation gap for AI-powered security tools.

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Thanks for reviewing! 🚀