[docs] Add missing client/.env example in README

[gaurikhairnar-live]

Description:

The "Setup Environment Variables" section in the README provides example .env files for server/ and bot/ but completely skips client/. The installation instructions say to create .env files in all three directories, so a beginner following the guide will be confused about what variables the frontend needs.

What is required: Add a client/.env example block in the README showing the required frontend environment variables (e.g. VITE_API_URL).

Level: 🟢 Beginner / 🟡 Easy-Intermediate (needs checking the actual client code to find what env vars are used)

[github-actions]

Thank you for raising this issue!

We'll review it as soon as possible. We truly appreciate your contributions! ✨

Meanwhile make sure you've visited the README.md, CONTRIBUTING.md, and CODE_OF_CONDUCT.md before creating a PR for this. Also, please do NOT create a PR until this issue has been assigned to you. 😊

[gaurikhairnar-live]

Hii @DeadIndian, I have raised this issue, I would like to work on this issue, please assign it to me.

[gaurikhairnar-live]

Thanks @DeadIndian, I'll start working on it.

[gaurikhairnar-live]

@DeadIndian, this issue has been resolved.
PR submitted by me as a GSSoC 2026 contributor.
Please review and merge 🙏

PR Link: #142