Update FAN.md

Find your device's brand code [here](https://github.com/smartHomeHub/SmartIR/blob/master/Docs/FAN.md#available-codes-for-fan-devices) and add the number in the `device_code` field. The compoenent will download it to the correct folder. If your device is not working, you will need to learn your own codes and place the .json file in `smartir/codes/fan/` subfolders. Please note that the `device_code` field only accepts positive numbers. The .json extension is not required.

## Configuration variables:

**name** (Optional): Name to use in the frontend<br />

**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.

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

**controller_send_service** (Required): The service that will be used to send the commands. Only `broadlink_send_packet` (Broadlink controller) is currently supported.<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 />

fan:

  - platform: smartir

    name: Living room fan

    name: Bedroom fan

    unique_id: bedroom_fan

    device_code: 1000

    controller_send_service: switch.broadlink_send_packet_192_168_10_10

    power_sensor: binary_sensor.fan_power