add files for custom grafana image with provisioned dashboards

grafana/provisioning/dashboards/dashboards.yml

@@ -0,0 +1,13 @@
+apiVersion: 1
+
+providers:
+  - name: "Dashboard provider"
+    orgId: 1
+    type: file
+    disableDeletion: false
+    updateIntervalSeconds: 10
+    allowUiUpdates: true
+    editable: true
+    options:
+      path: /etc/grafana/dashboards
+      foldersFromFilesStructure: true