Updated documentation for KNX platform (#4575)

* Documentation for https://github.com/home-assistant/home-assistant/pull/11978

* typo

source/_components/scene.knx.markdown

@@ -0,0 +1,34 @@
+---
+layout: page
+title: "KNX Scene"
+description: "Instructions on how to integrate KNX Scenes into Home Assistant."
+date: 2018-02-03 20:00
+sidebar: true
+comments: false
+sharing: true
+footer: true
+logo: knx.png
+ha_category: Scene
+ha_release: "0.63"
+---
+
+The `knx` scenes platform allows you to trigger [KNX](http://www.knx.org) scenes.
+
+The `knx` component must be configured correctly, see [KNX Component](/components/knx).
+
+```yaml
+# Example configuration.yaml entry
+scene:
+  - name: Romantic
+    platform: knx
+    address: 8/8/8
+    scene_number: 23
+```
+
+Configuration variables:
+
+- **name** (*Optional*): A name for this device used within Home Assistant.
+- **address**: KNX group address of the binary sensor.
+- **scene_number** KNX scene number to be activated.
+
+