Add CI and CodeCov badges to README

[glenn-jocher]

@kalenmike @hassaanfarooq01 adds CI and CodeCov badges to README

🛠️ PR Summary

_{Made with ❤️ by Ultralytics Actions}

🌟 Summary

Introduction of CI and Codecov badges to the HUB-SDK README.

📊 Key Changes

• Added Continuous Integration (CI) status badge.
• Incorporated Codecov coverage badge.

🎯 Purpose & Impact

• Purpose: To provide immediate visibility of the build status and test coverage to developers and users.
• Impact: Enhances transparency and trust in the HUB-SDK by showcasing its build stability and code quality 📈. Users and contributors can now quickly assess the project's health directly from the README.

[glenn-jocher]

@kalenmike @hassaanfarooq01 note Codecov badge is empty for now until CI tests begin to work correctly, then codecov results will be automatically uploaded to codecov and badge will show a percentage :)

[glenn-jocher]

@kalenmike merging PR!