remove wrapper height once loaded

I'm using the `height` prop with a roughly estimated value to prevent all items from loading immediately (since their initial height is 0, as long as the images have not been loaded). once an item has loaded, I'd like to remove the height / set it to `auto`.

it would be nice if the lib provided an option for this. — in the meantime, what would be the easiest way to achieve this?

Start by inspecting the component's height prop and the lifecycle used when children or images finish loading; no specific file or test is named in the issue. Done means an option can remove the wrapper height or set it to auto after an item has loaded, with coverage for the resulting behavior.

Written by the indexing model from the issue text.