message: chore(readme): adjust note about instability around futures
diff: @@ -23,7 +23,9 @@ hyper makes use of "async IO" (non-blocking sockets) via the
  [Tokio](https://tokio.rs) and [Futures](https://docs.rs/futures) crates.
  Be aware that hyper is still actively evolving towards 1.0, and is likely
  -to experience breaking changes before stabilising. You can also see the
  +to experience breaking changes before stabilising. However, this mostly now
  +around the instability of `Future` and `async`. The rest of the API is rather
  +stable now. You can also see the
  [issues in the upcoming milestones](https://github.com/hyperium/hyper/milestones).
  ## Contributing
  