Added new game Brain Blitz 🎮

[WAZIR77]

PR Description 📜

Adds the BrainBlitz game to the project and provides supporting assets, documentation, and a gamesData entry so the game appears on the site.

How to test / QA
Run the app locally:
npm install
npm start
Open http://localhost:3000 and verify the main site still loads.

What I changed
Added a project README updates for BrainBlitz with detailed rules, quick start, and embedded placeholder screenshots.
Added four placeholder screenshots (SVG) into public so the README shows inline previews.
Added a minimal assets/js/gamesData.json entry and a placeholder thumbnail in assets/images/ so BrainBlitz can be listed on the games index.
Created the required assets subfolders where they were missing.

---

Mark the task you have completed ✅

• I follow CONTRIBUTING GUIDELINE & CODE OF CONDUCT of this project.
• I have performed a self-review of my own code or work.
• My changes generates no new warnings.
• I have followed proper naming convention showed in CONTRIBUTING GUIDELINE
• I have added screenshot for website preview in assets/images
• I have added entries for my game in GameZone's README.md
• I have added README.md in my Game folder
• I have specified the respective issue number for which I have requested the new game.
• I have added my Game to gamesData.json file and it is loading properly on main website as intended.

Thank you soo much for contributing to our repository 💗

[kunjgit]

Thank you @WAZIR77 ,for creating the PR and contributing to our GameZone 💗
Review team will review the PR and will reach out to you soon! 😇
Make sure that you have marked all the tasks that you are done with ✅.
Thank you for your patience! 😀

[kunjgit]

Thank you @WAZIR77 , for your valuable time and contribution in our GameZone 💗.
It’s our GameZone, so Let’s build this GameZone altogether !!🤝
Hoping to see you soon with another PR again 😇
Wishing you all the best for your journey into Open Source🚀