Document that pipelining exists

Currently pipelining seems to be supported, but it's not really described much outside of the implementation, as far as I can tell.

I think it would be good to at least have some place that's hard to miss that users will immediately notice, so that they can be aware of this functionality existing.

Optionally, it would be good to describe the design of the implementation somewhere, but I think that advertising the feature to users is way more important.

If you have any suggestions on where this would go, I'd be happy to make a PR.