https://www.darktable.org/usermanual/en/shortcuts.html
views/lighttable/preview z
views/lighttable/view next space
views/lighttable/view prev backspace
views/lighttable/rate reject r
views/lighttable/rate 0 0
views/lighttable/rate 1 1
views/lighttable/rate 2 2
views/lighttable/rate 3 3
views/lighttable/rate 4 4
views/lighttable/rate 5 5
<Primary> Control
views/darkroom/zoom close-up <Alt>1
views/darkroom/zoom fill <Alt>2
views/darkroom/zoom fit <Alt>3