I presume what you’re requesting is exactly what explained from @ypy , this possibility will be probably exposed for uploading them together with the .scad file and .stl files functional to the script itself.
I - as a programmer - think that when your script will be executed a copy of the script and all supporting files (.SVG, .PNG, .STL) will be copied to a temporary location and the script executed from there.
This could also be useful for opening a way to multi-.scad-file script allowing everyone to use third party libraries in their scripts.
I hope this will be the evolution of Parametric Model Maker in the near future.