Add blackbird media player component (#5056)

source/_components/media_player.blackbird.markdown

@@ -0,0 +1,70 @@
+---
+layout: page
+title: "Blackbird 8x8 HDMI Matrix Switch"
+description: "Instructions on how to integrate Monoprice Blackbird 4k 8x8 HDBaseT Matrix Switch into Home Assistant."
+date: 2018-03-29 16:35
+sidebar: true
+comments: false
+sharing: true
+footer: true
+logo: monoprice.svg
+ha_category: Media Player
+ha_release: 0.68
+ha_iot_class: "Local Polling"
+---
+
+The `blackbird` platform allows you to control [Monoprice Blackbird Matrix Switch](https://www.monoprice.com/product?p_id=21819) using a serial connection.
+
+To add a Blackbird device to your installation, add the following to your `configuration.yaml` file:
+
+```yaml
+# Example configuration.yaml entry
+media_player:
+  - platform: blackbird
+    type: serial
+    port: /dev/ttyUSB0
+    zones:
+      1:
+        name: Living Room
+    sources:
+      3: 
+        name: BluRay
+```
+
+{% configuration %}
+type:
+  description: The type of device connection - serial or socket
+  required: true
+  type: string
+port: 
+  description: The serial port to which Blackbird matrix switch is connected. Either port or host must be defined.
+  required: optional
+  type: string
+host:
+  description: The IP address of the Blackbird matrix switch. Either port or host must be defined.
+  required: optional
+  type: string
+zones:
+  description: This is the list of zones available. Valid zones are 1,2,3,4,5,6,7,8. Each zone must have a name assigned to it.
+  required: true
+  type: int
+  keys:
+    name:
+      description: The name of the zone.
+sources:
+  description: The list of sources available. Valid source numbers are 1,2,3,4,5,6,7,8. Each source number corresponds to the input number on the Blackbird matrix switch. Similar to zones, each source must have a name assigned to it.
+  required: true
+  type: int
+  keys:
+    name:
+      description: The name of the source.
+{% endconfiguration%}
+
+### {% linkable_title Service `BLACKBIRD_SETALLZONES` %}
+
+Set all zones to the same input source. This service allows you to immediately synchronize all the TVs in your home. Regardless of `entity_id` provided, all zones will be updated. 
+
+| Service data attribute | Optional | Description |
+| ---------------------- | -------- | ----------- |
+| `entity_id` | yes | String that points at an `entity_id` of a zone.
+| `source` | no | String of source name to activate.