TODO:

Add preview on/off switch
Show how smaller the file is after dithering
Implement more dithering algorithms (issue #28)
Replace color amount selector with predefined custom palettes (also issue #28)
Switch to different UI design (Paleta seems like a good candidate)
Add spring animation for hiding bottom sheet
Add scroll and touch drag gestures for triggering bottom sheet hide animation

Issues:

When opening image in dither page, the options used on previous image won't be applied on loaded image preview (lack of options retention mechanism)