Add support for Grafana

This patch enables support for Grafana and provides a new dashboard.
diff --git a/metadata/service/support.yml b/metadata/service/support.yml
index 2594e43..1328b79 100644
--- a/metadata/service/support.yml
+++ b/metadata/service/support.yml
@@ -9,3 +9,5 @@
         enabled: true
       sphinx:
         enabled: false
+      grafana:
+        enabled: true