README: newer Vault init command
README: newer Vault init command

Got a warning message:

```
WARNING! The "vault init" command is deprecated. Please use "vault operator
init" instead. This command will be removed in Vault 0.11 (or later).
```
hashicorp/nomad,dvusboy/nomad,nak3/nomad,nak3/nomad,nak3/nomad,dvusboy/nomad,burdandrei/nomad,nak3/nomad,nak3/nomad,dvusboy/nomad,hashicorp/nomad,nak3/nomad,burdandrei/nomad,dvusboy/nomad,burdandrei/nomad,hashicorp/nomad,burdandrei/nomad,burdandrei/nomad,dvusboy/nomad,hashicorp/nomad,dvusboy/nomad,dvusboy/nomad,burdandrei/nomad,hashicorp/nomad,nak3/nomad,burdandrei/nomad,hashicorp/nomad