argparse: add help texts
argparse: add help texts

zerovm/zerovm-cli,zerovm/zerovm-cli,zerovm/zpm,zerovm/zpm,zerovm/zerovm-cli,zerovm/zpm,zerovm/zerovm-cli,zerovm/zpm,zerovm/zerovm-cli,zerovm/zerovm-cli,zerovm/zpm,zerovm/zpm