Update README.md with pypi badges

[glenn-jocher]

@kalenmike @hassaanfarooq01 add pypi version and downloads badges.

🛠️ PR Summary

_{Made with ❤️ by Ultralytics Actions}

🌟 Summary

Added PyPI badges to the hub-sdk README.

📊 Key Changes

• Inserted PyPI version badge.
• Added download statistics badge.

🎯 Purpose & Impact

• Increased Visibility: The badges serve as a quick visual indicator of the hub-sdk package's current version and its popularity based on downloads.
• User Convenience: With badges, users can immediately see if they are using the latest version and how trusted the package is within the community.
• Potential Impact: May boost user confidence and encourage more downloads and usage of the hub-sdk package. 📈