Block a user
add new tiles right at the "end" of the existing tiles instead of interspersing them
keeping in mind that an ID can be an arbitrary string, maybe it's worth filtering the set of IDs to just the type that bitsy naturally produces (base36), finding the highest one and incrementing it…
add new tiles right at the "end" of the existing tiles instead of interspersing them
change output file name to game name
if user loads a file, the output file should have the same name (possibly with a suffix)
separate colour-mapping from bitsy palette?
idea: copy the "new palette" colour inputs above the palette selection. add a default option to the palette selection called "as above". leave the "new palette" option as is.
if bg/fg are a part of SelectedPalette they will need to be separated out in the application state.
SelectedPalette will need a new enum variant.
render_preview() will need a new step to map the background/foreground to the desired colours, if selected palette is not "as above".