Supporting typing

[mattxwang]

Hello! The team over at @stylelint is now using support-hyperlinks to show links in terminal output (see stylelint/stylelint#5835). Currently, we've manually defined types for the package, though I think first-class/integrated support would be great!

Do you have a preferred way of doing this with support-hyperlinks (ex bundling it with the package, creating something under @types/, etc.)? Happy to contribute however I can!