docs: update image in github repo

README.md

@@ -10,7 +10,7 @@
 Grafana is an open source, feature rich metrics dashboard and graph editor for
 Graphite, Elasticsearch, OpenTSDB, Prometheus and InfluxDB.
 
-![](http://grafana.org/assets/img/start_page_bg.png)
+![](http://grafana.org/assets/img/features/dashboard_ex1.png)
 
 - [Install instructions](http://docs.grafana.org/installation/)
 - [What's New in Grafana 2.0](http://docs.grafana.org/guides/whats-new-in-v2/)