Nginx plus dashboard additions (#155)

* Add information on confuring NginxProxy resource for dashboard

* Replace api.md file with file on main

* Add small feedback and use document address blocks

Author: bjee19

content/ngf/how-to/data-plane-configuration.md

@@ -361,7 +361,7 @@ spec:
       mode: ProxyProtocol
       trustedAddresses:
       - type: CIDR
-        value "76.89.90.11/24"
+        value: "76.89.90.11/24"
 EOF
 ```
 

content/ngf/how-to/monitoring/dashboard.md

@@ -30,3 +30,30 @@ The dashboard will look like this:
 {{< img src="/ngf/img/nginx-plus-dashboard.png" alt="">}}
 
 {{< note >}} The [API](https://nginx.org/en/docs/http/ngx_http_api_module.html) used by the dashboard for metrics is also accessible using the `/api` path. {{< /note >}}
+
+### Configure dashboard access through NginxProxy
+
+To allow access to the NGINX Plus dashboard from different sources than the default `127.0.0.1`, we can use the NginxProxy resource
+to allow access to other IP Addresses or CIDR blocks.
+
+The following NginxProxy configuration allows access to the NGINX Plus dashboard from the IP Addresses `192.0.2.8` and 
+`192.0.2.0` and the CIDR block `198.51.100.0/24`:
+
+```yaml
+apiVersion: gateway.nginx.org/v1alpha1
+kind: NginxProxy
+metadata:
+   name: ngf-proxy-config
+spec:
+   nginxPlus:
+      allowedAddresses:
+         - type: IPAddress
+           value: 192.0.2.8
+         - type: IPAddress
+           value: 192.0.2.0
+         - type: CIDR
+           value: 198.51.100.0/24
+```
+
+For more information on configuring the NginxProxy resource, visit our [data plane configuration]({{< ref "data-plane-configuration.md" >}}) document
+which explains how to either configure an NginxProxy resource on installation, manually create an NginxProxy resource, or edit an existing NginxProxy resource.