feature: keymap aliasing

[MattSturgeon]

Currently if you wish to have multiple keymaps that do the same thing, you must either duplicate your definition for each alias or map a list of alias strings into a list of keymap attribute sets.

It may be handy to provide an aliases option accepting null, str or listOf str. If used, the keymap will be created for key as well as each alias.

If this is considered unnecessary feature bloat, perhaps document an example somewhere (README, Wiki, or docs) demonstrating how map can be used to produce duplicate keymaps?

[MattSturgeon]

@traxys this is probably wontfix for the same reason as #1214?

I guess, at most, the scope of this issue could be reduced to documenting an example of mapping a list of string-keys into multiple keybinds.

If you think such an example adds more value than confusion...

[traxys]

Yeah I think like #1214 this is a bit out of the scope of nixvim.

[traxys]

But we could add a section Tips & Tricks to the user guide were we could add Nix snippets to do stuff like this (and maybe to simulate something like #1214)