Add italic figures

oneeighth, threeeighths, fiveeighths, seveneighths,
onethird, twothirds, zero.superior, four.superior,
five.superior, six.superior,seven.superior, eight.superior, nine.superior,
zero.inferior, one.inferior, two.inferior, three.inferior, four.inferior,
five.inferior, six.inferior, seven.inferior, eight.inferior, nine.inferior