Web perf: Make homepage image more performant

[machikoyasuda]

This is an issue tracked in #2487

Acceptance Criteria

The goal of this ticket is to take whatever actions are necessary to make the homepage image on Mobile and Desktop load more efficiently. The steps recommended by the Google web.dev team:

• Serve images in next-gen format like WebP and AVIF for better compression, over PNG or JPEG: https://web.dev/articles/serve-images-webp
• Responsive images: https://web.dev/articles/serve-responsive-images
• Preload responsive image: https://web.dev/articles/preload-responsive-images

Additional context

Remember to bench mark the app (time to first byte, etc) before and after the ticket.