Add deprecation notice

Signed-off-by: Tim Smith <tsmith@chef.io>

README.md

@@ -2,6 +2,10 @@
 
 [![Build Status](https://travis-ci.org/chef-cookbooks/compat_resource.svg?branch=master)](https://travis-ci.org/chef-cookbooks/compat_resource) [![Cookbook Version](https://img.shields.io/cookbook/v/compat_resource.svg)](https://supermarket.chef.io/cookbooks/compat_resource)
 
+## DEPRECATION
+
+This cookbook was written to backport Chef functionality and resources to older versions of Chef. The last backport brought functionality from Chef 12.19 to 12.1-12.18\. Based on chef-client version support policy outlined [RFC-092](https://github.com/chef/chef-rfc/blob/master/rfc092-dependency-update-cadence.md#cookbook-and-ecosystem-tooling-support) we support the prior 6 months of chef-client releases in current community cookbooks and Chef 12.19 shipped in Feb 2017\. If you need the functionality provided in this cookbook you will need to update to Chef 12.19+. As Chef 12 goes EOL in April 2018 we highly recommend you upgrade to Chef 13\. See <https://blog.chef.io/2017/03/29/upgrading-chef-client-13/> for more information on the upgrade process.
+
 This cookbook backports functionality introduced in the latest chef-client releases to any chef-client from 12.1 onwards. This includes [Custom Resource](https://docs.chef.io/custom_resources.html) functionality, notification improvements, as well as new resources added to core chef. It allows for the usage of these new resources in cookbooks without requiring the very latest Chef client release.
 
 ## Backported functionality
@@ -27,12 +31,6 @@ This cookbook backports functionality introduced in the latest chef-client relea
 
 - none
 
-## Discouragement Policy
-
-This repo is not necessarily deprecated, but its use is being discouraged.  Based on the policy in [RFC-092](https://github.com/chef/chef-rfc/blob/master/rfc092-dependency-update-cadence.md#cookbook-and-ecosystem-tooling-support) we now only support the prior 6 months of chef-client releases in current community cookbooks.  So as of Jul 2017 (for example) we only
-support back to chef-client 12.18.31.  Users are expected to track current versions of Chef 12/13 for current community cookbook support and within a 6 month window to migrate to
-new versions of chef-client.  As a result this cookbook is no longer viewed as being particularly necessary (and was always somewhat problematic).
-
 ## Usage
 
 To use this cookbook, put `depends 'compat_resource'` in the metadata.rb of your cookbook. Once this is done, you can use all the new custom resource features to define resources. It Just Works.