Improve help text output by the default help subcommand

[rgoldberg]

The help text output by the default help subcommand doesn't seem proper to me:

1. The USAGE section doesn't show -h, --help, or --version if they are autogenerated
2. The USAGE section doesn't indicate that <subcommand> is optional, or that it can be followed by additional arguments
3. The OPTIONS section lists --version before -h, --help, but I think they should be sorted alphabetically
4. The SUBCOMMANDS section doesn't show help … Show help information., which I think should be inserted alphabetically in the subcommand list

ArgumentParser version:

main

Swift version: Paste the output of swift --version here.

swift-driver version: 1.127.14.1 Apple Swift version 6.2.1 (swiftlang-6.2.1.4.8 clang-1700.4.4.1)
Target: arm64-apple-macosx26.0

Checklist

• If possible, I've reproduced the issue using the main branch of this package
• I've searched for existing GitHub issues

Steps to Reproduce

Run the help subcommand of a command that has both a default help subcommand and that has CommandConfiguration.version set. They needn't exist together, but doing this shows both problems at once.

Expected behavior

Top-level help output:

OVERVIEW: Command

USAGE: cmd [(-h | --help) [<subcommand>] | --version | <subcommand> *…]

OPTIONS:
  -h, --help              Show help information.
  --version               Show the version.

SUBCOMMANDS:
  a                       A
  b                       B
  c                       C
  help                    Show help information.

Actual behavior

Top-level help output:

OVERVIEW: Command

USAGE: cmd <subcommand>

OPTIONS:
  --version               Show the version.
  -h, --help              Show help information.

SUBCOMMANDS:
  a                       A
  b                       B
  c                       C

[dickoff]

The USAGE section doesn't show -h, --help, or --version if they are autogenerated

I personally find the way this works desirable. For commands with many options, the USAGE line can get quite long. By always having (-h | --help) and --version there it's adding more noise than signal to a line that's trying to be information dense.

Semantically I'd also argue that --help is not actually part of the "usage" of the command. It's useful for getting information about the command, but an invocation of the command to do what its run function is programmed to do would never include the --help option.

[rgoldberg]

Not every command (regardless of SAP) supports -h and/or --help, so, to me, it makes sense to document all supported use cases.