I'm spinning Trisquel Docker images

I'm making unofficial Docker images for Trisquel available at
https://hub.docker.com/r/kpengboy/trisquel/.

Docker's a way to make containers for testing things in isolated
environments; you can read more about it on various places on the web. I've
found it pretty convenient to, for example, temporarily try out one package
without having to deal with how to uninstall it later. It's also useful for
doing things like installing experimental packages without worrying about
them messing up your real system, and many more things.

Some more popular distros like Debian, Ubuntu, Fedora, etc. have base images
officially supported by Docker; I'm making Trisquel images in the likeness of
these other distros' images.