[Feature Request] - Background image for tracing purposes

[Arkaliasus]

Slade: v3.2.4 Operating System: Windows

Feature Request The ability to be able to place a background inside the main editor pane to be used like tracing paper so we can draw lines over the top of it.

imagine the fun you could have with a satellite image or something and visualise it more efficiently. it would probably need a setting for it to be toggled on or off as well as maybe a keybind for ease.