feat: use different font to display example keys

[ermshiperete]

The font currently used to display the keys to type in the example makes it hard to see the difference between some keys, e.g. uppercase i and lowercase l. It would be better to use a different font where all characters can be distinguished.

For example on https://keymanweb.com/#am,Keyboard_gff_amharic I misread the second-to-last key as uppercase i instead of lowercase l and then wondered why the output didn't match the word shown in the example.