docs: add instructions for how to do docker "by hand" for early evaluation/testing

[Xe]

some basic bits about how you might want to do the network setup and also example docker run invocations

[chip-hubb]

I guess it would be easier with a real world example for a static website.
I'm also finding difficulties installing Anubis (docker compose) and native Nginx.
It would be also nice to understand if there is a minimal working configuration to start from and customizing from there.

The instructions are fragmented and bit confusing.

For instance in the nginx example you proxypass to "http://anubis."
Cool! but is anubis in /etc/hosts? is it defined in some other place like an nginx upstream?

Thanks in advance.