Add Ultralytics Discord badge

[glenn-jocher]

@Burhan-Q added Discord badge to Template repo

🛠️ PR Summary

_{Made with ❤️ by Ultralytics Actions}

🌟 Summary

Enhancement of project documentation with added Discord community badge.

📊 Key Changes

• Added a Discord badge to the README for easy access to the Ultralytics community.

🎯 Purpose & Impact

• Engagement: Encourages community interaction by providing a direct link to the Ultralytics Discord server.
• Support: Facilitates easier access to support and networking for both new and existing users.
• Visibility: Increases the visibility of community discussions and resources related to Ultralytics projects. 🤝 ⚙️