Add helpInformation to typings

[jharrilim]

Missing type for Commander.prototype.helpInformation:

commander.js/index.js

Lines 1085 to 1129 in 1c1ffca

	Command.prototype.helpInformation = function() {
	var desc = [];
	if (this._description) {
	desc = [
	this._description,
	''
	];
	var argsDescription = this._argsDescription;
	if (argsDescription && this._args.length) {
	var width = this.padWidth();
	desc.push('Arguments:');
	desc.push('');
	this._args.forEach(function(arg) {
	desc.push(' ' + pad(arg.name, width) + ' ' + argsDescription[arg.name]);
	});
	desc.push('');
	}
	}
	var cmdName = this._name;
	if (this._alias) {
	cmdName = cmdName + '|' + this._alias;
	}
	var usage = [
	'Usage: ' + cmdName + ' ' + this.usage(),
	''
	];
	var cmds = [];
	var commandHelp = this.commandHelp();
	if (commandHelp) cmds = [commandHelp];
	var options = [
	'Options:',
	'' + this.optionHelp().replace(/^/gm, ' '),
	''
	];
	return usage
	.concat(desc)
	.concat(options)
	.concat(cmds)
	.join('\n');
	};

[shadowspawn]

This is as intended since helpInformation is marked in the JSDoc with @api private. We do not document the private api calls in the TypeScript.

[jharrilim]

Ok makes sense. I was thinking maybe it should be declared as public so that I may get the string and not always write to stdout (perhaps another stream), but maybe I am designing my program wrong.