Use the same format for nested commands

[yorinasub17]

If we have nested commands (e.g kubergrunt eks configure), then the help text for the second level is still using the default urfave template. This updates it to use the same one as the app level:

Original:

NAME:
   kubergrunt eks - Helper commands to configure EKS, including setting up operator machines to authenticate with EKS.

USAGE:
   kubergrunt eks command [command options] [arguments...]

COMMANDS:
     configure  Set up kubectl to be able to authenticate with EKS.
     token      Get token for Kubernetes using AWS IAM credential.

OPTIONS:
   --help, -h  show help

Updated:

Usage: kubergrunt eks [--help] command [options] [args]

Helper commands to configure EKS, including setting up operator machines to authenticate with EKS.

Commands:

   configure  Set up kubectl to be able to authenticate with EKS.
   token      Get token for Kubernetes using AWS IAM credential.
   help, h    Shows a list of commands or help for one command

[brikis98]

Good catch, thx!