MINOR: da: Using ARG12 macro for the sample fetch and the convertor.

Regarding the minor update introduced in the
cd6c3c7cb4fdc9cf694b62241840e3fea30e03dd commit, the DeviceAtlas
module is now able to use up to 12 device properties via the
new ARG12 macro.
diff --git a/README b/README
index 13aa3b2..3e600e3 100644
--- a/README
+++ b/README
@@ -259,11 +259,11 @@
 
 All HTTP headers via the sample / fetch
 
-    http-request set-header X-DeviceAtlas-Data %[da-csv-fetch(primaryHardwareType,osName,osVersion,browserName,browserVersion)]
+    http-request set-header X-DeviceAtlas-Data %[da-csv-fetch(primaryHardwareType,osName,osVersion,browserName,browserVersion,browserRenderingEngine)]
 
 Single HTTP header (e.g. User-Agent) via the convertor
 
-    http-request set-header X-DeviceAtlas-Data %[req.fhdr(User-Agent),da-csv-conv(primaryHardwareType,osName,osVersion,browserName,browserVersion)]
+    http-request set-header X-DeviceAtlas-Data %[req.fhdr(User-Agent),da-csv-conv(primaryHardwareType,osName,osVersion,browserName,browserVersion,browserRenderingEngine)]
 
 # Mobile content switching with ACL