Migrate Contributor Spotlight from Gatsby to Vite + React with modern UI redesign

[rana-ashutosh-singh-04]

Overview

This PR migrates the Contributor Spotlight website from Gatsby.js to a modern
Vite.js + React.js stack and introduces a refreshed UI/UX design.

Key Changes

• Migration from Gatsby.js to Vite.js
• React upgrade and dependency modernization
• Redesigned landing page and contributor spotlight cards
• Improved responsiveness and accessibility
• Performance optimization using Vite build tooling
• Social profile links added for contributors

Impact

The new implementation improves performance, simplifies development, and
provides a more modern user experience while keeping compatibility with
the Jenkins.io ecosystem.

[rana-ashutosh-singh-04]

Hi maintainers,

This PR proposes a migration of the Contributor Spotlight website
from Gatsby to Vite + React with a redesigned UI.

I would appreciate feedback on whether this approach aligns with the
direction for modernizing the Contributor Spotlight project.

Thank you!