[Feature request] Option to start bars from 0

[Ingvix]

I'd like for bars to not show characters if there's no activity on their frequency. So there'd be no single line of bar stumps if there's no sound. I'm using cli-visualizer as a sort of background visualizer on my desktop and especially with stereo view it's a bit annoying that there's always a visible row even if there's nothing playing. Currently I've settled with a mono view with the terminal window little off the screen so the first line never shows but I think I'd like better to use the stereo view if this feature would be implemented.