Mention podman & rootless containers

[emanuelb]

Podman is alternative to docker, it's already pre-installed in fedora & other related os, thus can you mention it as alternative (after testing it's working) aka the only dependency is either docker or podman. also rootless containers is already fully supported in recent docker&podman, for more info: https://rootlesscontaine.rs/ so also worth to mention if it works when running under rootless containers.