fix the background image in the output pane with scrolling

[loiswells97]

When you scroll in the visual output pane the background image does not continue past the fold

Images that can be used for a tiling background:
https://www.figma.com/file/Rbn27JvH8A8wwqagKSReIq/Code-Editor---Component-library?node-id=1025-8496&t=BBE4ANkWcyWLeh5Y-4