Deno compatibility

[gr2m]

I spent some time on testing with Deno.

Things look good, I even added a smoke test:
#83

However loading the type-only modules (@octokit-next/types*) is not working as expected.

First, there is a problem with https://esm.sh that I described at esm-dev/esm.sh#433. I found a workaround.
But then I ran into a problem with Deno itself: it doesn't seem to parse the types of Type-only packages, unless I'm missing something: denoland/deno#16239

It does work in the TypeScript playground and with node code edited in VS code. But Deno doesn't seem to be able to handle it at this point 🤷🏼