Documentation for DirecTV component (#659)

* Create media_player.directv.markdown

* Added directv logo

source/_components/media_player.directv.markdown

@@ -0,0 +1,30 @@
+---
+layout: page
+title: "DirecTV"
+description: "Instructions how to integrate DirecTV receivers into Home Assistant."
+date: 2016-07-19 01:0+0000
+sidebar: true
+comments: false
+sharing: true
+footer: true
+logo: directv.png
+ha_category: Media Player
+ha_release: "0.25"
+---
+
+The [DirecTV](http://www.directv.com/) receivers will be automatically discovered if you enable the [discovery component](/components/discovery/).
+
+The `directv` media player platform can also be forced to load by adding the following lines to your `configuration.yaml`:
+
+```yaml
+# Example configuration.yaml entry
+media_player:
+  platform: directv
+  host: 192.168.1.10
+  name: DirecTV Living Room
+```
+
+Configuration variables:
+
+- **host** *Optional*: Use only if you don't want to scan for devices.
+- **name** *Optional*: Use to give a specific name to the device.