Add complete README for JavaScript30 practice repository

[Komali0706]

📌 Description

This pull request adds a clean and structured README.md file to the repository. The README includes:

• Project introduction
• What I learned
• List of completed JavaScript30 projects
• Technologies used
• Purpose of the repository
• Author section

🧩 Why This Change?

The repository did not have a proper README earlier.
Adding one improves clarity, readability, and makes the project look complete and professional.

✔️ Changes Made

• Created and added a new README.md file
• Added project details, learning points, and author information

🧪 Testing

No code changes were made — only documentation.
Everything builds and runs normally.

🙌 Ready to Merge

This PR is simple and safe to merge. Please review and merge.