Decide on the domain name and launch a landing page for the whitepaper

[jancurn]

We bought whitepaper.actor, specs.actor, and specification.actor - I'd go with the first one.

Let's use GitHub pages for this to keep it simple. We just need some way to break down the long page - but perhaps that's not needed? For inspiration, see e.g. https://playbook.samaltman.com/