Remove 'help' subcommand from command-line tool

[dougbu]

• kpm help packages add fails with a System.Exception: TODO: Error: unrecognized argument 'add'
  • this command is not an alias for the less-common kpm packages help add (that one works)
• kpm packages add -? oddly describes the target packages directory as the "[source]"
• other kpm packages subcommands have similar issues in their help

[davidfowl]

This is the same bug as #547

[dougbu]

• thought command and subcommand options should implicitly contain parent options #547 was about placement of options, not the sub-commands themselves?
  • are you saying we internally treat help (which looks like a sub-command) as an alias for --help? that's not obvious even from the help
• even the second bullet?

[ChengTian]

kpm help packages: shows help info of packages, which is a subcommand of kpm. In this case, help is a subcommand of kpm command.
kpm packages help add shows help info of add, which is a subcommand of kpm packages. In this case, help is a subcommand of kpm packages command.

kpm help packages add is invalid because the subcommand help of kpm only accepts one argument, which should be one of its peers (a subcommand of kpm).

The behavior is well-defined and consistent. But seems people don't like this consistency because it's not intuitive enough. @davidfowl , do we want to remove help subcommand and only use --help|-h option?

[davidfowl]

Yes