add requirements to readme file

diff --git a/README.md b/README.md
index 08e9d01fe31d403a68bd4e459c92ee682676b8ac..328b15500544a00528322de78a5c043fa32057e2 100644 (file)
--- a/README.md
+++ b/README.md
@@ -34,6 +34,12 @@ known valid paths for getData() :
  * data/letinfo.json
  * data/Status.json
  
+PHP requirements
+============= 
+ * PHP >= 5.4.0
+ * PHP extension `rrd` (for rrd graphs)
+ * PHP extension `mcrypt`
+
 rrdtool integration
 =============