Type classes: Omit explicit instance name

[gasi]

The compiler change to make instance names optional was introduced in v0.14.2: https://github.com/purescript/purescript/releases/tag/v0.14.2

[thomashoneyman]

Yea, these instances are preserved across core / contrib until 0.15 because it’s a breaking change to remove them (it means losing support for 0.14.0 and 0.14.1). I think it’d be preferable to mention they’re optional.

I believe there’s another docs page where we talk about instance names being used for readable JavaScript that we could crib from?

[JordanMartinez]

This hasn't been merged because feedback hasn't been addressed. It wouldn't take much to finish it.