ssh-auth-none-demo command

ssh-auth-none-demo is a demo SSH server that's meant to run on the public internet (at 188.166.70.128 port 2222) and highlight the unique parts of the Tailscale SSH server so SSH client authors can hit it easily and fix their SSH clients without needing to set up Tailscale and Tailscale SSH.

Connections are allowed using any username except for "denyme". Connecting as "denyme" will result in an authentication failure with error message.