Custom the key select mapping for Shift or Alt when English mode.

[Lak4CYUT]

Is your feature request related to a problem? Please describe. Because the screen of mobile device is usually tight, there are so many keyboard is support to switch some key with "Shift on (Alt on)". It is not only a ~ z but also include symbols such as ! -> 1, @ -> 2, like the really keyboard.

If we can configure/design our own mapping, it can avoid to bigger the keyboard or switch the keyboard. I think it will be a good idea.

Describe the solution you'd like Maybe a new engineer for ASCII mode just like "punctuator".

Describe alternatives you've considered n/a

Additional context n/a