--help/-h only in GLOBAL OPTIONS?

[decentral1se]

Checklist

• Are you running the latest v3 release? The list of releases is here.
• Did you check the manual for your release? The v3 manual is here.
• Did you perform a search about this feature? Here's the GitHub guide about searching.

What problem does this solve?

--help/-h appears in both options/global options for sub-commands and that is noisy.

Solution description

Support only specifying --help/-h as a global option.

Describe alternatives you've considered

There is currently a (potentially unknown?) hack to make this work. What you need to do:

Set cli.Help on your root command (otherwise you get Incorrect Usage: flag: help requested error):

	cli.HelpFlag = &cli.BoolFlag{
		Name:    "help",
		Aliases: []string{"h, H"},
		Usage:   "Show help",
	}

Then set HideHelpCommand: true on the root command.

Then set HideHelp: true on all sub-commands.

Then --help/-h only appears in GLOBAL OPTIONS and not OPTIONS and you do not receive the Incorrect Usage: flag: help requested error.

[decentral1se]

There is an additional inconsistency that sub-commands that are not leaf commands show --help/-h in OPTIONS regardless of the above hack. And HideHelp: true then actually hides the flag.

[dearchap]

@decentral1se want to make a PR for the fix ? Would be happy to review.