I once started a little bash for automate creating fatfree projects ... creating folder structures ... git and composer support ...
I can´t remember I think it works but is still dev-*
there you have one option to start a docker container.
maybe this helps to get you started. As ved says, there is nothing special about it.
link a php docker to your code and your done ...
But indeed it would be nice to have a "official" fatfree container or vagrant with all the stuff installed you can use with
f3.