Because I will be repeating similar code across multiple prototypes (for example a menu) I'd like to abstract it into a module. Is it possible to include assets (images) in there?
There is an npm module for this kind of stuff: https://www.npmjs.com/package/npm-assets As far as I know, Framer works well with npm, so perhaps you could try to make this work with Framer?
He's basically saying 'haha you want to do real code in framer? Here's some real code!'
You can base64 encode them or include them along with your module.
Just throwing out other options. You can host the images on somewhere and use links to incorporate them as long as you're cool with always needing internet. Also, I'm not sure what the images are, but if they're shapes you can embed the SVGs into the code.