[Bug] README does not document required podman.sock for run.sh/smoketest.sh

[andrewazores]

run.sh always tries to mount the rootless podman.sock with the following:

    -v "$XDG_RUNTIME_DIR"/podman/podman.sock:/run/user/0/podman/podman.sock:Z \

if the user does not have this socket file (ie. the user podman socket is not enabled) then the script execution fails.

README should probably be updated to list systemctl --user enable --now podman.socket as a prerequisite to running the run.sh/smoketest.sh scripts.