Provide help in more ways

[lawik]

We should be able to prefix any command with help to get the help and another good convention is that any -h turns the command into a help command as well.

[lawik]

Okay, the help command worked. I had the escript version shadowing my brew version (on both machines no less).

The -h would still be great :)

[lawik]

Oh, and it will always just print the base help so it doesn't give you help for nh help firmware sign for example.