Upload zip files to products

What version of Invoice Ninja are you running? ie v4.5 / v5 v5.6.31-C123 What environment are you running? Self-Hosted Have you searched existing issues/requests? Yes, found something similar on the forums but not exactly the same Screenshots If applicable, add screenshots to help explain your request/question. Additional context Add any other context about the request/question here. I'd like to upload a zip file (I'd prefer different kind of files, but I can work with zips) to a Product (and not to the Invoice as the request I found on the forum). My use case is quite specific so I won't get mad if you say "forget it" :) I'm saving mainly "3d printing projects" as products as a matter of keeping the things organized and I'd like to upload a zip of the file / object once is ready to print (NOTE: not the 3d file itself, but the sliced file ready for the printed, usually a .gcode or .chitu file extensions ranging from …