"default"
        // Left/right arrow keys step between horizontal slides, up/down
        // arrow keys step between vertical slides. Space key steps through
        // all slides (both horizontal and vertical).
        //
        // "linear"
        // Removes the up/down arrows. Left/right arrows step through all
        // slides (both horizontal and vertical).
        //
        // "grid"
        // When this is enabled, stepping left/right from a vertical stack
        // to an adjacent vertical stack