Option to disable default global help and version flags

[plexigras]

i would like to be able to only conditionally display the help which is currently not possible.

cac/src/Cac.js

Lines 31 to 39 in 03822fc

	this.option('version', {
	alias: 'v',
	type: 'boolean',
	desc: 'Display version'
	}).option('help', {
	alias: 'h',
	type: 'boolean',
	desc: `Display help (You're already here)`
	})

[egoist]

We can add an option help here:

cac/src/Cac.js

Line 19 in 03822fc

constructor({ bin, pkg } = {}) {

Maybe add one for version too 😄

[egoist]

btw in which case you don't want to show help when a flag like --help appears?

[plexigras]

i just want to have custom help for subcommands.

i can make a pr 😄