Vastly improve the help output.

- Don't print 'unknown subcommand' at the top of the help message.  The help message now clearly instructs the user to provide a subcommand.
- Clarify the usage line.  Subcommand is required.  Don't echo invalid input back out in the usage line (what the...???).  args renamed to paths, because that's what all the args are referred to elsewhere.
- List the available subcommands immediately following the usage line.  It's the one required argument, after all.
- Slightly improve the extra documentation for the build, test, and doc commands.
- Don't print 'Available invocations:' at all.  It occurred immediately before 'Available paths:'.
- Clearly state that running with '-h -v' will produce a list of available paths.

0 files changed, 0 insertions, 0 deletions