Update Preact link due to git.io deprecation
Update Preact link due to git.io deprecation

Update https://git.io/preact to point to https://github.com/preactjs/preact,
since git.io is disappearing in a few days:
https://github.blog/changelog/2022-04-25-git-io-deprecation/
developit/preact-without-babel,developit/preact-without-babel