Add header/footer/flags with dropdown arrows #2
Description
Add header/footer/flags fields like TIO, Vyxal & APLgolf have. There should be a dropdown icon next to them, and they should be open by default iff there was a change in that field.
Eg. if someone changed the header & the code, only the code & header should be dropped down when you open the link. And perhaps the arrow could be shaded orange if its field was changed.