[REQUEST] hide mapped key in menu

[SArpnt]

Feature

add an option to hide custom mapped keys in menus like "goto"

Usecase

if you press g or G, it opens the "goto" or "goto (extend)" menu, and by default you can press GHJKL (with shift!) to do the same actions as ghjkl. GHJKL do not show up in the menu.
i've remapped these keys to neio, but this doesn't make NEIO work, i have to add those bindings manually. if i use the same docstring, they clutter up the menu. if i use an empty docstring or don't set one, they still show up in the menu with no doc text.

Alternatives

if #2557 gets merged and makes all those keys visible then i don't have a good example and i won't care for the feature. maybe someone else will want it for a different reason?