unusual help documentation for pass-through flags

[matthewleon]

example

$ psc-package build --help
Usage: psc-package build [-d|--only-dependencies] [`purs compile`-options]
  Build the current package and dependencies

Available options:
  -d,--only-dependencies   Compile only the package's dependencies
  `purs compile`-options   Options passed through to purs compile; use -- to
                           separate
  -h,--help                Show this help text

The documentation format for "purs-compile-options" seems to stray from UNIX command line norms. Ideally the usage line would more clearly illustrate the usage of -- to separate pass-through arguments.

Here is what stack does, for comparison:

$ stack exec --help
Usage: stack exec CMD [-- ARGS (e.g. stack ghc -- X.hs -o x)] ([--plain] |
                  [--[no-]ghc-package-path] [--[no-]stack-exe] [--package ARG]
                  [--rts-options RTSFLAG]) [--help]
  Execute a command