Add HEOS play_media URL documentation (#9261)

* Add play url docs

* Tweaks

* ✏️ Tweak

source/_components/heos.markdown

@@ -43,6 +43,29 @@ host:
 A connection to a single device enables control for all devices on the network. If you have multiple HEOS devices, enter the host of one that is connected to the LAN via wire or has the strongest wireless signal.
 </p>
 
+## {% linkable_title Services %}
+
+### {% linkable_title Service `media_player.play_media` %}
+
+#### {% linkable_title Play Url %}
+
+You can play a URL through a HEOS media player using the `media_player.play_media` service. The HEOS player must be able to reach the URL. Example service data payload:
+
+```json
+{
+  "entity_id": "media_player.office",
+  "media_content_type": "url",
+  "media_content_id": "http://path.to/stream.mp3"
+}
+```
+
+| Attribute              | Description
+| ---------------------- | ----------- | ----------- |
+| `entity_id`            | `entity_id` of the player to play the URL
+| `media_content_type`   | Set to the value `url`
+| `media_content_id`     | The full URL to the stream
+
+
 ## {% linkable_title Notes %}
 
 - HEOS groups are not currently supported.