Add docs for ingress with path (#22143)

Signed-off-by: LucasBoisserie <lucas.boisserie@gmail.com>

stable/grafana/Chart.yaml

@@ -1,6 +1,6 @@
 apiVersion: v1
 name: grafana
-version: 5.0.18
+version: 5.0.19
 appVersion: 6.7.3
 kubeVersion: "^1.8.0-0"
 description: The leading tool for querying and visualizing time series and metrics.

stable/grafana/README.md

@@ -168,6 +168,22 @@ You have to add --force to your helm upgrade command as the labels of the chart
 | `downloadDashboardsImage.pullPolicy`      | Curl docker image pull policy                 | `IfNotPresent`                                          |
 | `namespaceOverride`                       | Override the deployment namespace             | `""` (`Release.Namespace`)                              |
 
+### Example ingress with path
+
+With grafana 6.3 and above
+```yaml
+grafana.ini:
+  server:
+    domain: monitoring.example.com
+    root_url: "%(protocol)s://%(domain)s/grafana"
+    serve_from_sub_path: true
+ingress:
+  enabled: true
+  hosts:
+    - "monitoring.example.com"
+  path: "/grafana"
+```
+
 ### Example of extraVolumeMounts
 
 ```yaml