public function renderHelp()
    {
        echo $this->renderVersion();

        // Usage
        echo Line::begin('Usage:', Line::YELLOW)->nl();
        echo Line::begin()
            ->indent(2)
            ->text('generator [context:]subject [options]')->nl(2);

        // Options
        echo Line::begin('Options:', Line::YELLOW)->nl();
        echo Line::begin()
            ->indent(2)
            ->text('--help', Line::MAGENTA)
            ->to(21)
            ->text('-h', Line::MAGENTA)
            ->text('Display this help message.')
            ->nl(2);

        // Generators
        echo Line::begin('Available generators:', Line::YELLOW)->nl();
        foreach ($this->generators as $name => $config) {
            echo Line::begin()
                ->indent(2)
                ->text($name, Line::MAGENTA)
                ->to(24)
                ->text(Generator::create($name, $config)->getDescription())
                ->nl();
        }
    }