height and the minHeight of the widget it renders apply to the same
container, and minHeight is a floor, so it wins. The default here matches
bars()'s default minHeight for that reason. To render an output shorter
than 500px, lower both — barsOutput(height = "300px") alone stays 500px
tall until the widget is built with bars(..., minHeight = 300).
Usage
barsOutput(outputId, width = "100%", height = "500px")
renderBars(expr, env = parent.frame(), quoted = FALSE)