Add lazy loading to testimonial images in index.html

[Adityacode-hub]

Description

Added native HTML loading="lazy" attribute to all testimonial tags in index.html to prevent eager loading during initial page load.

Also updated alt attributes for better accessibility and SEO.

Fixes #51

Type of change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• This change requires a documentation update

##Improvement

• Improves page load performance
  -Reduces initial bandwidth usage
  -Enhances accessibility

##File Changed

• index.html

.

[github-actions]

Thank you and congratulations 🎉 for opening your very first pull request in student-program

[Adityacode-hub]

Hi maintainers 👋

I’ve added lazy loading to testimonial images in index.html as discussed in the issue.

All checks are passing now. Please review when possible.

Thank you!