message: Update README to mention CNCF
  This is a requirement for graduation.
diff: C++ L7 proxy and communication bus
  +Envoy is hosted by the [Cloud Native Computing Foundation](https://cncf.io) (CNCF). If you are a company that wants to help shape the evolution of technologies that are container-packaged, dynamically-scheduled and microservices-oriented, consider joining the CNCF. For details about who's involved and how Envoy plays a role, read the CNCF [announcement](https://www.cncf.io/blog/2017/09/13/cncf-hosts-envoy/).
  +
  ## Documentation
  * [Offical documentation](https://envoyproxy.github.io).
  