Consider removing FromList instance for NonEmpty

[Martoon-00]

In #238 I have added FromList typeclass with fromList that behaves very similar to GHC.Exts.IsList.fromList.

And it is defined for NonEmpty too. This means that the following code:

a = fromList [] :: NonEmpty a

as well as the following code:

{-# LANGUAGE OverloadedLists #-}

a = [] :: NonEmpty a

will fail. However, unlike in IsList, currently we will have a callstack attached to the error.

We should consider pros and cons of removing this instance.

[treeowl]

I'm not really a fan of such an instance myself. It's not hard to just use the constructor properly instead.

[Martoon-00]

I also agree that removing the instance would be better.