Make note of https://transfer.sh shutdown in the README

README.md

@@ -1,5 +1,10 @@
 # transfer.sh [![Gitter](https://badges.gitter.im/Join%20Chat.svg)](https://gitter.im/dutchcoders/transfer.sh?utm_source=badge&utm_medium=badge&utm_campaign=&utm_campaign=pr-badge&utm_content=badge) [![Go Report Card](https://goreportcard.com/badge/github.com/dutchcoders/transfer.sh)](https://goreportcard.com/report/github.com/dutchcoders/transfer.sh) [![Docker pulls](https://img.shields.io/docker/pulls/dutchcoders/transfer.sh.svg)](https://hub.docker.com/r/dutchcoders/transfer.sh/) [![Build Status](https://travis-ci.org/dutchcoders/transfer.sh.svg?branch=master)](https://travis-ci.org/dutchcoders/transfer.sh)
 
+*Note: [as of September 29th,
+2017](https://twitter.com/dutchcoders/status/913835197237465089), the
+reference instance of [https://transfer.sh](https://transfer.sh) has been shut
+down.*
+
 Easy and fast file sharing from the command-line. This code contains the server with everything you need to create your own instance.
 
 Transfer.sh support currently the s3 (Amazon S3) provider and local file system (local).