held key : add alternative key trigger parameter

[vrenaville]

Is your feature request related to a problem? Please describe.
actually the modifier of the held key, support modifier and layer swtiching not alternative key stroke

Describe the solution you'd like
if I press the arrow right a long time, it s mapped a the home key. I use it a lot with my moonlander

Describe alternatives you've considered
I use a layer for that but it not a real alternative