treat ^h (ctrl+h) as backspace

[p00ya]

macOS, bash and UNIX users will be familiar with the ubiquitous ^h code for deleting backwards a single character (it works just the same as the backspace key, because historically the backspace key actually sent this keycode). Some references:

• https://support.apple.com/en-us/HT201236 (under "Document shortcuts")
• https://en.wikipedia.org/wiki/Backspace#^H

Any native text field (or indeed Chrome/Safari text field unless they're doing special input processing) will treat ^h as backspace on macOS. Monkeytype ignores ^h.

It would be good for monkeytype to treat ^h as backspace either by default or via opt-in. It's typically much more ergonomic (e.g. H is on the home row right index finger on qwerty/dvorak/colemak) and it's quite frustrating to have the muscle-memory not work on monkeytype.

I can send a PR if this seems acceptable. Please let me know if it should be configurable/opt-in.

[Miodec]

#1325 should fix this completely