Deprecate this library in favor of generics-rep

[paf31]

I don't think we have enough evidence to say with certainty whether this library should be replaced by generics-rep yet, but I wanted to create an issue to track it.

[matthewleon]

In the meantime, would it be possible to add some brief guidance to the READMEs of both repos? Which lib should be used, and when? What are the advantages/disadvantages?

[paf31]

👍 Sounds like a good idea

[thomashoneyman]

I was about to use this library in favor of generics-rep based on name alone until seeing this issue and a note in the Slack channel.

I am very much in favor of adding a brief note to the readme of this repository recommending generics-rep instead; surely others will stumble across this and think it's the "official" repository as well.