Update light.x10.markdown (home-assistant#4312)

bbrendon · fabaff · commit ca1f2868e025 · 2018-01-03T21:04:45.000+01:00
name is not optional.
diff --git a/source/_components/light.x10.markdown b/source/_components/light.x10.markdown
@@ -25,11 +25,12 @@ light:
   - platform: x10
     devices:
       - id: a2
+        name: Guest Room
       - id: a3
         name: Bedroom Lamp
 ```
 
 Configuration variables:
 
 - **id** (*Required*): Device identifier. Composed of house code and unit id.
-- **name** (*Optional*): A friendly name for the device. By default *id* from the device is used.
+- **name** (*Required*): A friendly name for the device.
