'elm --help' output could be improved

[Qqwy]

When running $ elm --help to see how the executable can be used...

Expected output

Elm Platform 0.18.0 - a way to run all Elm tools

Usage: elm <command> [<args>]

Available commands include:

  make      Compile an Elm file or project into JS or HTML
  package   Manage packages from <http://package.elm-lang.org>
  reactor   Develop with compile-on-refresh and time-travel debugging
  repl      A REPL for running individual expressions

You can learn more about a specific command by running things like:

  elm make --help
  elm package --help
  elm <command> --help

In all these cases we are simply running 'elm-<command>' so if you create an
executable named 'elm-foobar' you will be able to run it as 'elm foobar' as
long as it appears on your PATH.

Actual output

Could not find command `--help`. Maybe there is a typo?

Default commands include:

  make      Compile an Elm file or project into JS or HTML
  package   Manage packages from <http://package.elm-lang.org>
  reactor   Develop with compile-on-refresh and time-travel debugging
  repl      A REPL for running individual expressions

When you try to run the command `--help` we actually search for an
  executable named elm---help. Are you able to run elm---help?
  Is it on your PATH?

---

While the information is there, clearly the output is confusing since --help is treated as the name of an executable.

I think it would help if we could check for this flag (and possibly -h and maybe also plain the word help) directly, especially since --help is a recognized flag to see more information about each of these separate commands (like elm-package --help).

[evancz]

It should be nicer with 0.19