adds deprecation warning

README.md

@@ -5,6 +5,18 @@ Installs and configures [HAProxy](http://www.haproxy.org/).
 
 Based on https://github.com/devops-coop/ansible-haproxy.
 
+Deprecated Features
+-------------------
+
+
+- `reqadd`, `reqdel`, `respadd` and similar functions for header manipulation are deprecated since haproxy version 2.0 (https://cbonte.github.io/haproxy-dconv/2.0/configuration.html#4-reqadd). Please use `http_request` (https://cbonte.github.io/haproxy-dconv/2.0/configuration.html#http-request) as described in the section `Role Variables` below. The actions are described in the haproxy doc.
+  - example:
+    ```yaml
+    http_request:
+      - action: 'set-header'
+        param: 'X-Forwarded-Proto "https"'
+    ```
+
 Role Variables
 --------------
 
@@ -239,7 +251,6 @@ Example
 
 
 
-
 License
 -------