Adding documentation for Sense HAT lights (#2530)

* Adding documentation for Sense HAT lights.

Lights component page plus cross referencing from the Sense HAT
sensors component page.

* Update light.sensehat.markdown

source/_components/light.sensehat.markdown

@@ -0,0 +1,27 @@
+---
+layout: page
+title: "Sense HAT Light"
+description: "Instructions how to setup Sense HAT LED lights within Home Assistant."
+date: 2017-04-29 16:00
+sidebar: true
+comments: false
+sharing: true
+footer: true
+logo: sense-hat.png
+ha_version: 0.44
+ha_category: Light
+ha_iot_class: "Assumed State"
+---
+
+The `sensehat` light platform lets you control the [Sense HAT](https://www.raspberrypi.org/products/sense-hat/) board's 8x8 RGB LED matrix on your Raspberry Pi from within Home Assistant.
+
+To add `sensehat` to your installation, add the following to your `configuration.yaml` file:
+
+```yaml
+# Example configuration.yaml entry
+light:
+  platform: sensehat
+  name: SenseHAT
+```
+
+For setting up the Sense HAT sensors, please see the [Sense HAT sensor component](/components/sensor.sensehat/).

source/_components/sensor.sensehat.markdown

@@ -150,3 +150,5 @@ This fix has been tested with a clean install of:
 and
  
 * [Home-Assistant 0.37.1](https://home-assistant.io/getting-started/installation-raspberry-pi-all-in-one/)
+
+For setting up the Sense HAT's RGB LED matrix as lights within Home Assistant, please see the [Sense HAT light component](/components/light.sensehat/).