Doc: verbose instruction for building just one box
Doc: verbose instruction for building just one box

jpsecher/ubuntu,jrosengren/ubuntu,jcarley/ubuntu-vm,tbfisher/packer-ubuntu,kontrafiktion/ubuntu,flandr/ubuntu,samepage-labs/ubuntu,falconlulu/ubuntu,quarkslab/packer-ubuntu,jpsecher/ubuntu,kontrafiktion/ubuntu,cmbant/ubuntu,falconlulu/ubuntu,muratayusuke/ubuntu,NERC-CEH/ubuntu,muratayusuke/ubuntu,grafjo/ubuntu,quarkslab/packer-ubuntu,kenhkan/packer-templates,erikh/ubuntu,dragon788/ubuntu,grafjo/ubuntu,njohns-grovo/ubuntu,boxcutter/ubuntu,njohns-grovo/ubuntu,defn/basebox-ubuntu,tbfisher/packer-ubuntu,jcarley/ubuntu-vm,erikh/ubuntu,NERC-CEH/ubuntu,quarkslab/ubuntu,dragon788/ubuntu,cmbant/ubuntu,quarkslab/ubuntu,jrosengren/ubuntu,samepage-labs/ubuntu,boxcutter/ubuntu,pro-vagrant/ubuntu,flandr/ubuntu,pro-vagrant/ubuntu,kenhkan/packer-templates