docs: add detail on launching autoscaler external plugins.
docs: add detail on launching autoscaler external plugins.

burdandrei/nomad,burdandrei/nomad,burdandrei/nomad,hashicorp/nomad,dvusboy/nomad,hashicorp/nomad,hashicorp/nomad,burdandrei/nomad,dvusboy/nomad,dvusboy/nomad,hashicorp/nomad,dvusboy/nomad,dvusboy/nomad,dvusboy/nomad,hashicorp/nomad,burdandrei/nomad,hashicorp/nomad,burdandrei/nomad,dvusboy/nomad,burdandrei/nomad