Add documentation for Apple TV (#1996)

source/_components/media_player.apple_tv.markdown

@@ -0,0 +1,60 @@
+---
+layout: page
+title: "Apple TV"
+description: "Instructions how to integrate Apple TV devices into Home Assistant."
+date: 2017-02-08 07:11
+sidebar: true
+comments: false
+sharing: true
+footer: true
+logo: apple.png
+ha_category: Media Player
+ha_iot_class: "Local Polling"
+ha_release: 0.38
+---
+
+The `apple_tv` platform allows you to control an Apple TV (3rd and 4th generation).
+
+<p class='note'>
+Currently you must have Home Sharing enabled for this to work. Support for pairing Home Assistant
+with your device will be supported in a later released.
+</p>
+
+## {% linkable_title Configuration %}
+
+If you want to automatically discover new devices, just make sure you have ``discovery:``in
+your ``configuration.yaml``. To manually add an Apple TV to your installation, add the following
+to your configuration file:
+
+```yaml
+# Example configuration.yaml entry
+media_player:
+  - platform: apple_tv
+    host: IP_ADDRESS
+    login_id: LOGIN_ID
+    name: NAME
+```
+
+Configuration variables:
+
+- **host** (*Required*): The IP-address of the device
+- **login_id** (*Required*): An identifier used to login to the device, see below
+- **name** (*Optional*): The name of the device used in the frontend
+
+In order to connect to the device you need a *login id*. The easiest way to obtain this identifier
+is to use the application ``atvremote``. It should be available in the same environment as you
+installed Home-Assistant. Just run it like this to scan for all devices (try again if a device
+is missing):
+
+```
+$ atvremote scan
+Found Apple TVs:
+ - Apple TV at 10.0.10.22 (login id: 00000000-1234-5678-9012-345678901234)
+```
+
+Just copy and paste the login id from the device you want to add. For more details about
+atvremote, see: [this page](https://github.com/postlund/pyatv/blob/master/docs/atvremote.rst).
+
+## Notes and Limitations
+
+- Pairing is currently not supported