a new machine: website and prometheus in digitalocean

This is basically a maybe. 

- [ ] `quinn-dougherty.com` at greater uptime than `yoneda` which is onprem
- [ ] [monitor](https://xeiaso.net/blog/prometheus-grafana-loki-nixos-2020-11-20/) `yoneda`'s uptime
- [ ] Autodeploy from ci server (which will remain on `yoneda`)