Replace the default Next.js `favicon.ico`

[twy30]

This issue may need to be break into smaller tasks

1. Draw a new favicon.ico
2. Update all assets with the new favicon.ico
   • web-app ( https://d4pi.com/ source code: https://github.com/d4pi/web-app/ )
   • Discord ( https://discord.gg/sxUMgj3VcA )
   • GitHub D4pi org ( https://github.com/d4pi )
   • Reddit ( https://www.reddit.com/r/D4pi/ )