Update README.md

Partially addresses https://jira.cfops.it/browse/PCX-1934.

Author: kodster28

README.md

@@ -1,6 +1,10 @@
 # mod_cloudflare for Apache #
 Copyright CloudFlare Inc. 2016
 
+## Deprecation notice ##
+
+Cloudflare no longer updates and supports mod_cloudflare, starting with versions Debian 9 and Ubuntu 18.04 LTS of the Linux operating system. We now support [mod_remoteip](https://support.cloudflare.com/hc/articles/200170786#C5XWe97z77b3XZV) for customers using Apache web servers.
+
 ## mod_cloudflare.c ##
 
 Based on mod_remoteip.c, this Apache extension will replace the remote_ip variable in user's logs with the correct remote IP sent from CloudFlare. The module only performs the IP substitution for requests originating from CloudFlare IPs by default.