Cool project! Please add a five minute demo video at the top of the Readme. Also I would change the name to something more unique. Naming is difficult but important in products and CS.
5 minute video in a readme ... Are you aware of how much data will need to load to display that? Maybe a link to such a video would be fine. But not 5 minutes embedded into the readme. You might get 30s for that as a reasonable video length.
video compression can be pretty good, and for an editor which is gonna be mostly a static image with just elements switched on and off, surely it can't be "that much". it can't be worse than some github pages with dozens of huge pngs
