When using fade, slides are still stacked, meaning links etc on lower slides are inaccessible

When using the fade options, slides are not actually set to `display: none` their visibility and opacity is just altered. This means that which ever slide is last in the list is the one which is actually clickable. For example, create a slideshow of images with links - https://codesandbox.io/s/7j6j388070 - No matter which slide is shown, you can only ever get to the link on the last slide.

Once a slide isn't visible it needs it's `display` property changing so it doesn't affect the other slides and sit on top of them.