[Ftr] Consider adding a tip for command --help

[lread]

Is your feature request related to a problem? Please describe.
When I invoke a cli-matic with the --help option I get a nice summary of help. For example:

> ./toycalc.clj --help
NAME:
 toycalc - A command-line toy calculator

USAGE:
 toycalc [global-options] command [command options] [arguments...]

VERSION:
 0.0.1

COMMANDS:
   add, a               Adds two numbers together
   sub, s               Subtracts parameter B from A

GLOBAL OPTIONS:
       --base N  10  The number base for output
   -?, --help

But there is no indication that I can get help on a command, for example via
./toycalc.clj add --help

Describe the solution you'd like
Add a tip to the overall help. Maybe something like:

NAME:
 toycalc - A command-line toy calculator

USAGE:
 toycalc [global-options] command [command options] [arguments...]

VERSION:
 0.0.1

COMMANDS:
   add, a               Adds two numbers together
   sub, s               Subtracts parameter B from A

  For help on a command follow the command with --help.

GLOBAL OPTIONS:
       --base N  10  The number base for output
   -?, --help

Describe alternatives you've considered
Perhaps a way of getting all help for all options and all commands at once would be useful.

Additional context
None

[lread]

If this makes sense to folks, I can submit a PR.

[l3nz]

I would not do it now, as I plan to do major changes as per #69

[lread]

Thanks for the reply, feel free to close this one if it makes sense to do so.