Added Experimental word in admin 'config' CLI help and admin.md

[msterin]

this just changes commands output a little:

[root@localhost:~] admin config --help
usage: vmdkops_admin.py config [-h] {init,status,mv,rm} ...

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

Init and manage Config DB to enable quotas and access control [EXPERIMENTAL]:

  {init,status,mv,rm}  action
    init               Init Config DB to allows quotas and access groups, aka
                       vmgroups
    status             Show the status of the Config DB
    mv                 Relocate Config DB from its current location [NOT
                       SUPPORTED YET]
    rm                 Remove Config DB

[root@localhost:~] admin config init --local
Warning: this feature is EXPERIMENTAL
Creating new DB at /etc/vmware/vmdkops/auth-db

[root@localhost:~] admin config init --datastore=vsanDatastore
Warning: this feature is EXPERIMENTAL
Creating new DB at /vmfs/volumes/vsanDatastore/dockvols/vmdkops_config.db
Creating a symlink to /vmfs/volumes/vsanDatastore/dockvols/vmdkops_config.db at /etc/vmware/vmdkops/auth-db