I was directed here from a GitHub issue here: https://github.com/syntax-tree/mdast-util-to-hast/issues/44.
I propose to support IDNs/Punycode in URLs so links like
[example](https://я.рф/я) could be encoded as
https://xn--41a.xn--p1ai/%D1%8F not as
https://%D1%8F.%D1%80%D1%84/%D1%8F (this percent-encoding breaks the link).