Better Biff instance, clean up

[sjoerdvisscher]

I tried to give this instance before and failed, but the applicative style methods make it really easy.

Here’s how it looks translated back to Arrow style: https://github.com/sjoerdvisscher/one-liner/commit/c0b713bdfa9e086329adafa6d84f09ebeb895471

[tomjaguarpaw]

Cool