Update MEDIA_PLAYER.md

**name** (Optional): The name of the device<br />

**unique_id** (Optional): An ID that uniquely identifies this device. If two devices have the same unique ID, Home Assistant will raise an exception.<br />

**device_code** (Required): ...... (Accepts only positive numbers)<br />

**controller_data** (Required): The data required for the controller to function. Enter the IP address of the Broadlink device **(must be an already configured device)** or the MQTT topic on which to send commands.<br />

**controller_data** (Required): The data required for the controller to function. Enter the IP address of the Broadlink device **(must be an already configured device)**, or the entity id of the Xiaomi IR controller, or the MQTT topic on which to send commands.<br />

**power_sensor** (Optional): *entity_id* for a sensor that monitors whether your device is actually On or Off. This may be a power monitor sensor. (Accepts only on/off states)<br />

## Example (using broadlink controller):

    power_sensor: binary_sensor.tv_power

```

## Example (using mqtt controller):

## Example (using xiaomi controller):

```yaml

smartir:

remote:

  - platform: xiaomi_miio

    host: 192.168.10.10

    token: YOUR_TOKEN

media_player:

  - platform: smartir

    name: Living room TV

    unique_id: living_room_tv

    device_code: 2000

    controller_data: remote.xiaomi_miio_192_168_10_10

    power_sensor: binary_sensor.tv_power

```

## Example (using mqtt controller):

```yaml

smartir:

media_player:

  - platform: smartir

    name: Living room TV

    unique_id: living_room_tv

    device_code: 3000

    controller_data: home-assistant/living-room-tv/command

    power_sensor: binary_sensor.tv_power

```