docs: update README to reflect React + Vite migration

[nehakathayat8077]

What this PR does

Fixes #100

The README was outdated and still referenced the old static
HTML/CSS/JS implementation. This PR updates it to reflect
the current React + Vite architecture.

Changes made

• Updated tech stack section to React 18, React Router DOM, Vite 5
• Replaced old project structure with React-based structure
• Updated installation steps to use npm install and npm run dev
• Added Available Scripts table with dev/build/preview commands
• Updated badges to show React and Vite instead of HTML/JS/CSS
• Kept Open Source section, Screenshots, Roadmap and Author intact
• Removed references to opening index.html directly in browser

[netlify]

✅ Deploy Preview for makeareadme ready!

Name	Link
🔨 Latest commit	204f598
🔍 Latest deploy log	https://app.netlify.com/projects/makeareadme/deploys/6a071326b4e7320008d1de5c
😎 Deploy Preview	https://deploy-preview-112--makeareadme.netlify.app
📱 Preview on mobile	Toggle QR Code... Use your smartphone camera to open QR code link.
🤖 Make changes	Run an agent on this branch

---

To edit notification comments on pull requests, go to your Netlify project configuration.