Add more details for the setup (#5528)

* Add more details for the setup

* Rephrase

source/_components/sensor.netdata.markdown

@@ -16,10 +16,34 @@ ha_iot_class: "Local Polling"
 
 The `netdata` sensor platform allows you to display information collected by [Netdata](http://my-netdata.io/).
 
+## {% linkable_title Setup %}
+
+Getting the details to configure the sensors is a bit tricky as Netdata uses different name for the `element:` value that is required. To get the value for the `data_group:` use Netdata's web interface. `1.` marks the name for the `data_group:`. `2.` are the names for the element to show in Home Assistant. The name that is shown can be different than the name under which the metrics are available.
+
+<p class='img'>
+  <img src='{{site_root}}/images/components/netdata/details.png' />
+</p>
+
+To check if the `element:` name matches the name in the Netdata frontend, use `curl` with the IP address of your Netdata instance, its port and the `data_group`:
+
+```bash
+$ curl -X GET "http://[Netdata_Instance]:19999/api/v1/data?chart=[data_group]&points=2&options=jsonwrap"
+{
+   "api": 1,
+   "id": "system.ipv4",
+   "name": "system.ipv4",
+[...]
+   "dimension_names": ["received", "sent"],
+   "dimension_ids": ["InOctets", "OutOctets"],
+[...]
+```
+
+- `dimension_names`: Names shown in the frontend.
+- `dimension_ids`: Names to use for `element`.
+
+
 ## {% linkable_title Configuration %}
 
-
-
 To add this platform to your installation, add the following to your `configuration.yaml` file:
 
 ```yaml