Add SVG version of CoreDNS

[NoeTerrier]

We could add svg version of CoreDNS, available here: https://github.com/coredns/logo/blob/master/Icon/CoreDNS_Colour_Icon.svg

[shollyethan]

Thanks for the link. Given the logo consists of basic shapes, I was able to easily recreate it myself and avoid the artifacts found in the linked SVG file (white borders from shape subtractions, etc.).

It has now been added to the collection: https://github.com/selfhst/icons/blob/main/svg/coredns.svg

FYI @miekg