a help overlay when the question-mark
        // key is pressed
        help: {{ help }},
        // Flags if it should be possible to pause the presentation (blackout)
        pause: {{ pause }},
        // Flags if speaker notes should be visible to all viewers
        showNotes: {{ show_notes }},
        // Global override for autolaying embedded media (video/audio/iframe)
        // - null:   Media will only autoplay if data-autoplay is present
        // - true:   All media will autoplay, regardless of