Create bootstrap script or tool

[Nicklas Frahm]

I would like to have a CLI or script that I can run against a fresh router after provisioning to do the following tasks:

• Set hostname
• Change user password

The tasks below should most likely be carried out via a service running inside k3s:

• Configure dynamic DNS
• Configure router ID and ASN

For more info consider the source file cmd/ic/zone/up.go.