Site Doc for Hotswap has a broken example

[morgen-peschke]

The site doc example of a rotating logger assumes an API that doesn't match the one provided by Hotswap.

The assumed API would be much easier to work with in certain cases, though would need to be less powerful than what's provided by Hotswap. I think the missing abstraction could be useful, a NonEmptyHotswap would provide similar value as NonEmptyList.

I've taken a stab at this in #4267, and it looks promising.