Improve PEGELONLINE docs according to new quality scale (#35940)

Co-authored-by: Franck Nijhof <frenck@frenck.nl>

source/_integrations/pegel_online.markdown

@@ -18,11 +18,35 @@ ha_integration_type: service
 
 This integration uses the data from the German Federal Waterways and Shipping Administration (_Wasserstraßen- und Schifffahrtsverwaltung des Bundes_) [PEGELONLINE](https://www.pegelonline.wsv.de/) to provide different [sensors](#sensors), based on the available data of the selected measurement station.
 
+## Data fetching and limitations
+
+The data are polled every 5 minutes. You can add as many measurement stations as want, there is no authentication needed nor any official usage limitation, but keep the "fair use" in mind.
+
 {% include integrations/config_flow.md %}
 
+### Step 1 - Location selection
+
+Select the area, where you want to search for available water measuring stations
+
+{% configuration_basic %}
+Latitude:
+    description: "The latitude of the center of the search area (_automatically filled by the location picker_)."
+Longitude:
+    description: "The longitude of the center of the search area (_automatically filled by the location picker_)."
+Radius:
+    description: "Search radius (_in km_)"
+{% endconfiguration_basic %}
+
+### Step 2 - Station selection
+
+{% configuration_basic %}
+Station:
+    description: "Select the measurement station you want to add."
+{% endconfiguration_basic %}
+
 ## Sensors
 
-Currently, the integration supports the following sensors:
+The following {% term sensors %} are created, based on the capabilities of the selected measurement station:
 
 | Sensor name | Common unit of measurement |
 | --- | --- |
@@ -34,3 +58,31 @@ Currently, the integration supports the following sensors:
 | Water level | cm |
 | Water temperature | °C |
 | Water volume flow | m³/s |
+
+## Usage example
+
+### Flood alert level notification
+
+Create an automation to get notified, when your local river reaches a specific flood alert level.
+
+```yaml
+mode: single
+triggers:
+  - trigger: numeric_state
+    entity_id:
+      - sensor.dresden_elbe_water_level
+    above: 500
+actions:
+  - action: notify.persistent_notification
+    metadata: {}
+    data:
+      message: Flood alert level 2 reached!
+```
+
+## Troubleshooting
+
+In any case, when reporting an issue, please enable [debug logging](/docs/configuration/troubleshooting/#debug-logs-and-diagnostics), restart the integration, and as soon as the issue reoccurs stop the debug logging again (_download of debug log file will start automatically_). Further _if still possible_, please also download the [diagnostics](/integrations/diagnostics) data. If you have collected the debug log and the diagnostics data, provide them with the issue report.
+
+## Remove the integration
+
+{% include integrations/remove_device_service.md %}