Make unsaved changes more prominent #49

I'm not exactly sure what the solution is here, but for some reason I had the impression when I clicked on "Add" for the submit nodes, that the change was saved automatically. Couple of ideas:

• Float the "Save" button so that it's always visible
• Float a toast notification at the top of the page (well, on top of the visible area) when there are unsaved changes
• Save anything that involves a button click after entering? Less sure about this... maybe at least make this consistent across pages