maas-cli tag commands needs help

[Diogo Matsubara]

For example:
$ maas-cli maas tags -h
usage: /usr/lib/python2.7/dist-packages/maascli/__main__.py maas tags
       [-h] COMMAND ...

optional arguments:
  -h, --help show this help message and exit

drill down:
  COMMAND
    new Create a new `Tag`.
    list List Tags.

ubuntu@autopkgtest:~$ maas-cli maas tags new -h
usage: /usr/lib/python2.7/dist-packages/maascli/__main__.py maas tags new
       [-h] [-d] [-k] [data [data ...]]

positional arguments:
  data

optional arguments:
  -h, --help show this help message and exit
  -d, --debug Display more information about API responses.
  -k, --insecure Disable SSL certificate check

The help for those commands needs to explain the arguments it accepts