Instructions for getting RaspBee I installed are incomplete
**Describe The Bug:**
The documentation on https://github.com/homebridge/homebridge-raspbian-image/wiki/How-To-Install-deCONZ-for-ConBee-or-RaspBee is saying that for a RaspBee I there is no further thing to be done. However this might be not always true.

**To Reproduce:**
1) install HomeBridge 1.3.4 on Raspberry Pi 2B
2) connect a RaspBee I to it
3) follow steps in https://github.com/homebridge/homebridge-raspbian-image/wiki/How-To-Install-deCONZ-for-ConBee-or-RaspBee
4) open the DeCONZ web interface and check the Firmware of the connected RaspBee (can be seen in Settings -> Gateway).

**Expected behavior:**
A number should be shown such as 26390500 for the firmware, which is not the case.

**Manual workaround:**
Looking at the DeCONZ install instructions https://phoscon.de/en/raspbee/install#raspbian that the very first step from the guide is also necessary.

sudo raspi-config

Interfacing Options → Serial

Would you like a login shell accessible over serial? → No
Would you like the serial port hardware to be enabled? → Yes
Note: Changes to access rights only become active after a restart.

**Additional notes:**
Not sure if the step 6 is also needed as I don't have the RP4 available for testing.

**Environment:**

* **Homebridge Raspberry Pi Image Version**: 
* **Node.js Version**: v14.16.0
* **NPM Version**: v7.6.3
* **Homebridge Version**: 1.3.4
* **Homebridge Config UI X Plugin Version**: 4.41.0
