docs: add contributors and last-commit badges to README

[varshiniml7]

📝 Description

Added two missing badges to the README header - Contributors badge (shows total contributor count) and Last Commit badge (shows repo activity).

🎯 Type of Change

• 🐛 Bug fix (non-breaking change which fixes an issue)
• ✨ New feature (non-breaking change which adds functionality)
• 🤖 New AI tool (adds a new tool under 100 lines)
• 💥 Breaking change (fix or feature that would cause existing functionality to not work as expected)
• 📚 Documentation update
• 🎨 Code style update (formatting, renaming)
• ♻️ Refactoring (no functional changes)
• ⚡ Performance improvement
• ✅ Test update
• 🔧 Configuration change
• 🔒 Security fix

📦 Which Tool(s)?

• AI Agent
• MCP Server
• Code Reviewer
• Mini RAG
• Commit AI
• Voice to Code
• Terminal AI
• Infrastructure/Docs
• New Tool: ___________

📏 Line Count Check (for new tools or major changes)

Not applicable - documentation update only.

✅ Checklist

• My code follows the project's style guidelines
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works (if applicable)
• New and existing unit tests pass locally with my changes
• Any dependent changes have been merged and published

📖 Documentation

• README updated (if needed)
• Tool-specific README created/updated
• Examples added/updated
• CHANGELOG.md updated

🧪 Testing

Not applicable - badge URLs are auto-generated by shields.io and verified to display correctly.

🖼️ Screenshots/Demos (if applicable)

Badges auto-render in GitHub README preview.

💡 Additional Context

These badges were requested in issue #22 to make the README more engaging and professional.

🔗 Related Issues

Closes #22

📊 Impact

• Breaking changes: No
• Performance impact: None
• Security impact: None

🎁 Bonus

Badges auto-update dynamically so no manual maintenance needed!