package/nerdctl: new package

nerdctl is a CLI for containerd (package docker-containerd) which is
drop-in compatible with the Docker Daemon CLI.

This allows using the lighter weight containerd daemon directly,
instead of via the additional docker daemon. It also implements
rootless mode.

https://github.com/containerd/nerdctl



Signed-off-by: Christian Stewart <christian@paral.in>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>