allow nvim for AUR install

[slbsh]

the install script for the aur package (ver. 12.12-1) requires either vim or gvim,
prob a good idea to optionally allow neovim and neovide.

No idea if this is cause of another dependency, just throwin it out there

[sonic2kk]

Thanks!

This would be better to request on the AUR page though. I think it was requested previously, the AUR package maintainer would be more suited to comment on whether or not nvim is an acceptable dependency.