Add SponsorKit

[mesqueeb]

https://github.com/antfu/sponsorkit

[jcbhmr]

It seems like sponsorkit is intended to be used to generate an SVG that's then hosted somewhere (likely in your dot-github https://github.com/jcbhmr/.github or user profile https://github.com/jcbhmr/jcbhmr repos) and then ![]() included in your readme? Right? 🤔

https://github.com/antfu/static 👈 this is where antfu hosts their sponsorkit stuff. i'd personally put mine in .github or my user profile.