admin-cli.md should be updated for tenant access set to keep it consistent with "-h" option output

[shuklanirdesh82]

#859 causes this inconsistency.

Interesting excerpt from an existing document

https://github.com/vmware/docker-volume-vsphere/blob/67cabe4b1672cf18ee2089f2a7f6e0b2d78f2f12/docs/user-guide/admin-cli.md#set

[root@localhost:~] /usr/lib/vmware/vmdkops/bin/vmdkops_admin.py tenant access set --name=tenant1 --datastore=datastore1 --allow-create --volume-maxsize=1000MB --volume-totalsize=2GB
tenant access set succeeded

[root@localhost:~] /usr/lib/vmware/vmdkops/bin/vmdkops_admin.py tenant access set -h
usage: vmdkops_admin.py tenant access set [-h]
                                          [--volume-totalsize Num{MB,GB,TB} - e.g. 2TB]
                                          --name NAME
                                          [--volume-maxsize Num{MB,GB,TB} - e.g. 2TB]
                                          [--allow-create] --datastore
                                          DATASTORE

on ESX:

[root@promc-2n-dhcp105-97:~] /usr/lib/vmware/vmdkops/bin/vmdkops_admin.py status
Version: 0.10.e7acd33-0.0.1

[root@promc-2n-dhcp105-97:~] /usr/lib/vmware/vmdkops/bin/vmdkops_admin.py tenant access set -h
usage: vmdkops_admin.py tenant access set [-h]
                                          [--volume-totalsize Num{MB,GB,TB} - e.g. 2TB]
                                          --name NAME
                                          [--volume-maxsize Num{MB,GB,TB} - e.g. 2TB]
                                          [--allow-create ALLOW_CREATE]
                                          --datastore DATASTORE

optional arguments:
  -h, --help            show this help message and exit
  --volume-totalsize Num{MB,GB,TB} - e.g. 2TB
                        Maximum total size of all volume that can be created
                        on the datastore for this tenant
  --name NAME           Tenant name
  --volume-maxsize Num{MB,GB,TB} - e.g. 2TB
                        Maximum size of the volume that can be created
  --allow-create ALLOW_CREATE
                        Allow create and delete on datastore if set to True;
                        disallow create and delete on datastore if set to
                        False
  --datastore DATASTORE
                        Datastore name

[shuklanirdesh82]

One more thing I would like to request here is to add some example or valid set of value for --allow-create option like it is added for ```--volume-totalsize/maxsize.

[--volume-maxsize Num{MB,GB,TB} - e.g. 2TB]
                                          [--allow-create ALLOW_CREATE]