Add X10 light documentation (#687)

* Add X10 light documentation

* Replace featured with ha_release in light.x10

source/_components/light.x10.markdown

@@ -0,0 +1,37 @@
+---
+layout: page
+title: "X10"
+description: "Instructions how to setup X10 devices within Home Assistant."
+date: 2016-07-27
+sidebar: true
+comments: false
+sharing: true
+footer: true
+logo: x10.gif
+ha_category: Light
+ha_iot_class: "Local Polling"
+ha_release: true
+---
+
+X10 support is integrated into Home Assistant as a light platform.
+
+Requires heyu x10 interface
+http://www.heyu.org
+
+To enable x10 lights, add something like this to your `configuration.yaml` file:
+
+```yaml
+    # Example configuration.yaml entry
+    light:
+    - platform: x10
+        lights:
+        - name: Living Room Lamp
+            id: a2
+        - name: Bedroom Lamp
+            id: a3
+```
+
+Configuration variables:
+
+- **id** (*Required*): Device identifier. Composed of house code + unit id.
+- **name** (*Optional*): A friendly name for the device. By default *id* from the device is used.