I have only been in a few jams and none of them had this so I dont understand...
Hey solodoesstuff! No worries — this is a requirement specific to this jam so people can rate the Design category properly.
Basically, just attach (or link) anything that shows your design process / creative work behind the game itself: PDFs, slides, pictures, Miro/Trello boards, storyboards, sketches, mood boards, design docs, asset trackers, etc. Shareable links are totally fine.
The idea is to let raters see the thinking and process, not just the final build. Let me know if you have any questions.