Guide: Add freeform image with relative path

[ElFlix]

For many images in my guide, I currently use formatting like this:

The reason is that I often need images that don't affect the formatting, so that images with transparency can fit just around the text boxes.
The biggest problem with this is that I can't share the project without adjusting the file path on every other system.

If possible, it would be nice to have some control over the "z-axis" -> how far it gets put in the background. Currently I believe the images are in front of text, if there is any overlap