Add Marathi translation for README

[vanshhedaoo29]

Summary

Add a Marathi translation of the main README file to improve accessibility for Marathi-speaking developers.

Changes

Created /readme/mr.md

Added Marathi entry to i18n.json

Linked Marathi README in the language list section of the root README.md

Context

Marathi is spoken by over 80 million people, primarily in the Indian state of Maharashtra and among diaspora communities worldwide. Adding a Marathi version of the README will make Lingo.dev more inclusive, help native developers understand the project better, and encourage open-source participation from regional contributors.

[vanshhedaoo29]

Please assign this issue to me. I’d like to work on it.

[IG-ABHINAV]

My Name is Abhinav Dhawan.
i would like to contribute to this issue.

[Gowtham2801031902]

My Name is Gowtham.
i would like to contribute to this issue.

[chitrasaindane]

Hi! I’m Chitra Saindane a native Marathi speaker and would love to contribute by translating the main README into Marathi. Please assign this issue to me. I can ensure the translation is clear, accurate, and natural for Marathi developers.

[maxprilutskiy]

This issue is currently blocked because Marathi (mr) is not yet supported as a locale in the Lingo.dev platform. We are working on adding support for this language and will unblock this issue once it's available.