To use GitHub as a package registry for Deno, you only need to replace github.com
with denopkg.com
like this:
https://denopkg.com/user/repo or repo@tag/path/to/file
Example:
import { opn } from 'https://denopkg.com/hashrock/deno-opn/opn.ts'
opn('https://denopkg.com')