Array docstrings

[zth]

I've done most of the docstrings, enough to get a new release out at least.

[glennsl]

Will you remove the unsafe from and fromWithMap functions as well?

[zth]

Will you remove the unsafe from and fromWithMap functions as well?

I was going to rename them fromUnsafe and fromWithMapperUnsafe as a first step.

[zth]

@glennsl I ended up removing them instead.

[zth]

Ready for review. @glennsl would you have a look at this too?

[glennsl]

Mostly nits, and most of them are repeated throughout, but I've avoided adding repetitive comments. So if you agree with a remark, it's a good idea to look over the rest for the same issue.

[zth]

Thanks for the good feedback @glennsl , I think I covered all of it. I'm going to merge this so we can get closer to a new release. Can rework any remaining issues here later on.