[docs]: Update README and add FAQ section for Azure DevOps MCP Server

[danhellem]

This pull request updates the README.md and introduces a new FAQ.md document to improve user guidance and address common questions about the Azure DevOps MCP Server.

Documentation enhancements:

• README.md: Reorganized the table of contents to include a new "Frequently Asked Questions" section and added a corresponding FAQ section with a link to the newly created FAQ.md file. [1] [2]
• docs/FAQ.md: Added a new FAQ document covering topics such as Azure DevOps Services support, connecting to multiple organizations, and setting a default project.

GitHub issue

#76

Associated Risks

None

✅ PR Checklist

• I have read the contribution guidelines
• I have read the code of conduct guidelines
• Title of the pull request is clear and informative.
• 👌 Code hygiene
• 🔭 Telemetry added, updated, or N/A
• 📄 Documentation added, updated, or N/A
• 🛡️ Automated tests added, or N/A

🧪 How did you test it?

Manual review

[github-actions]

Dependency Review

✅ No vulnerabilities or license issues or OpenSSF Scorecard issues found.

Scanned Files

None