Enhance Home Page UI with Hero Section, Features, and Responsive Design

[Lakshmihollat]

This PR revamps the PeerPrep Home Page to make it more engaging, visually appealing, and aligned with PeerPrep’s collaborative learning vision.

Changes made:

✨ Added a hero section with headline, subtext, and call-to-action buttons.
🎨 Introduced a modern layout with gradients, hover effects, and animations.
🧩 Added a Features Section (cards for collaboration, structured content, goals, etc.).
🌍 Created a Community Section to display active users, contributors, and countries.
💡 Added a How It Works section for easy onboarding.
📱 Improved responsiveness for desktop and mobile screens.
🖋️ Updated color palette and typography for better readability.
⚙️ Linked with existing navigation, authentication buttons, and footer.

Screenshot:

Closes Issue: #37

[github-actions]

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[Lakshmihollat]

Hello @radhika-droid
Please review this PR and merge it. Thank you.

[Lakshmihollat]

Hello @radhika-droid
Today is the last day of gssoc25, It was wonderful working with you on this project.
I request you to merge these 2 PRs and assign them with labels by end of today so i can be awarded points for them. Thank you.