add fun nas command to fun.js

[SquatsTonight]

>fun nas --help

  Usage: fun nas [options] [command]

  Operate your remote NAS file system locally.

  Options:

    -h, --help  output usage information

  Commands:

    info        Print nas config information, such as local temp directory of NAS.
    init        For each service with NAS config, create local NAS folder and deploy fun nas server service.
    sync        Synchronize the local NAS directory with the remote NAS file system.
    ls          List contents of remote NAS directory
    help [cmd]  display help for [cmd]