[Grml] zsh history completion via arrow keys

[Frank Terbeck]

Frank Terbeck wrote:
[...]
> I don't think we should wiggle around with the default settings too
> much. Things like this are pretty much up to anyone's subjective
> preferences, which is exactly why we do have facilities like zshrc.local
> and zshrc.pre in place.

Also, it turns out, that we already do have a binding that does
basically the same on <PageUp> and <PageDown>. So.... :)

(Missing this serves me right for not using our zsh setup myself...)

Regards, Frank