Doc for nadtcp media player component (#2368)

* Doc for nad7050 component

Initial commit.

* removed volume_step

* Revert "removed volume_step"

This reverts commit 3594e7b94a7da2c3d16060f3d831cd79bd45abc4.

* reader volume_step

* simplified example

* renamed component

* Made description more generic.

* more stuff

* Set release version

source/_components/media_player.nadtcp.markdown

@@ -0,0 +1,38 @@
+---
+layout: page
+title: "NAD tcp"
+description: "Instructions how to integrate the NAD D 7050 or C338 digital amplifiers into Home Assistant."
+date: 2017-06-07 20:00
+sidebar: true
+comments: false
+sharing: true
+footer: true
+logo: nad.png
+ha_category: Media Player
+ha_release: 0.47
+ha_iot_class: "Local Polling"
+---
+
+
+The `nadtcp` platform allows you to control the D7050 and C338 from Home Assistant via WiFi. Note that it has only been tested with the D 7050.
+
+To add a NAD amplifier to your installation, add the following to your `configuration.yaml` file:
+
+```yaml
+# Example configuration.yaml entry
+media_player:
+    platform: nadtcp
+    host: 192.168.0.112
+```
+
+Configuration variables:
+
+- **host** (*Required*): The IP address of your amplifier.
+- **name** (*Optional*): Name of the device. Default is NAD amplifier.
+- **min_volume** (*optional*): Minimum volume in dB to use with the slider. Default is `-60`
+- **max_volume** (*optional*): Maximum volume in dB to use with the slider. Default is `-10`
+- **volume_step** (*Optional*): The amount in dB you want to increase the volume with when pressing volume up/down. Default is 4 dB.
+
+The maximum volume level of the D 7050 amplifier is +10 db, minimum is -90.
+
+