Add Discord Badge

[glenn-jocher]

🛠️ PR Summary

_{Made with ❤️ by Ultralytics Actions}

🌟 Summary

Enhanced community engagement with Discord badge addition in README.

📊 Key Changes

• Integration of a Discord badge with a link to Ultralytics' community server alongside the existing Actions badge in the README file.

🎯 Purpose & Impact

• 🌐 Facilitates easier access to the Ultralytics community, encouraging users to join the discussion and get support.
• 🔗 Strengthens the project's community engagement by providing a direct link to the Discord server for live discussions, support, and networking.
• 🛠 Provides potential contributors with an additional channel to communicate and collaborate, potentially accelerating development and fostering a more vibrant community.