README.md in fastly-2.5.3 vs README.md in fastly-3.0.0

@@ -1,9 +1,15 @@
 # Fastly [![Build Status](https://travis-ci.org/fastly/fastly-ruby.svg?branch=master)](https://travis-ci.org/fastly/fastly-ruby)
 
 Client library for interacting with the Fastly web acceleration service [API](http://docs.fastly.com/api)
 
+### A Note About Authentication
+
+Authenticating with a username/password is deprecated and will no longer be available starting September 2020.
+
+Authenticating with an API Token is shown in the example section below. For more information on API Tokens, please see [Fastly's API Token documentation](https://developer.fastly.com/reference/api/auth/). For more information about authenticating to our API, please see our [Authentication section](https://developer.fastly.com/reference/api/#authentication).
+
 ## Examples
 
 Add fastly to your Gemfile:
 ```ruby
 gem 'fastly'
@@ -11,10 +17,11 @@
 
 Create a fastly client:
 
 ```ruby
 # some_file.rb
-# use {api_key: 'your-key'} or {user: 'username', password: 'password'} as login options
+# username/password authentication is deprecated and will not be available
+# starting September 2020; use {api_key: 'your-key'} as the login option
 fastly = Fastly.new(login_opts)
 
 current_user     = fastly.current_user
 current_customer = fastly.current_customer