docs: fix grammar and spelling in contribution guide

[MOHITKOURAV01]

Fix Grammar and Spelling Errors in Contribution Guide

Fixes grammar and spelling errors in the Contribution Guide (docs/contribution.md).

Changes Made

• Corrected "is developing by" → "is developed by".
• Fixed pluralization issue: "Create a ... messages" → "Create ... messages".

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Checklist

• Build: I've run npm build before committing and verified the bundle updates correctly.
• Tests: I've run npm test and confirmed all tests succeed.
• Docs: I've added or updated relevant documentation as needed.
• CoC: My changes follow the project's coding guidelines and Code of Conduct.
• Review: This PR represents original work and is not solely generated by AI tools.

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