Add CONTRIBUTING.md file to support contributors

[ananyasinha-1]

A contribution guide is currently missing from the repository. Adding a CONTRIBUTING.md file would help contributors understand how to get started, follow contribution standards, and submit pull requests correctly. This would make the contribution process more smooth and organized for everyone involved. I would like to work on adding this documentation.

[pushkarscripts]

Thanks for opening this issue! You can work on this.

The CONTRIBUTING.md should include:

• setup instructions
• contribution workflow
• branch naming convention
• PR guidelines
• coding style expectations

Please keep it beginner-friendly and concise.