Add Cleanlab to beginner-friendly projects

[Devatva24]

🚀 Add Cleanlab as a Beginner-Friendly Python Project

This pull request adds Cleanlab to the list of beginner-friendly open-source projects.

🧠 Why Cleanlab?

• Cleanlab is a data-centric machine learning library used to detect and fix label issues in datasets.
• The repository actively maintains issues labeled good first issue, making it welcoming for first-time contributors.
• Especially valuable for contributors interested in Python and Machine Learning.

✅ Checklist

• Project is open source and actively maintained
• Beginner-friendly issue labels exist
• Entry follows the existing format and guidelines

Adding Cleanlab will help new contributors discover a high-quality ML project and get started with open source more confidently.