Actually, installing RaspberryOS (or the older Raspbian) have always been simple and can be accomplished within a few steps requiring no scripts or complicated instructions.
- Download the image
- Download the application to write the image
- Insert SD/microSD into PC
- Write image
This is assuming the user needs to write the OS to more than one card. If they simply want to write an image one time, they can use the installation tool which does everything for you. Navigate to: raspberrypi.org/software and select the windows installer. It will let you select the version of the OS you want (I recommend RaspberryOS Lite) and what drive your SD is inserted into. Simply select "WRITE". It will download and install the image pretty quick/easy depending on your network speeds.
The next step is to install HG. There were issues with the installer when Gene stepped away leaving it difficult to install. However, those issues no longer exist and the standard installation works fine. The steps to install could be put into a script but it seems silly since that would actually make more work. Simply follow the installation guide.
Navigate to the HG homepage:
http://www.homegenie.itClick on the "Get Started" link on the upper right. Select "Download". If you scroll down on the right pane it will give you installation instructions for Window, Linux, etc. Under Linux (Ubuntu, Raspbian and others Debian derivatives) there are 4 lines of code that will install HG on a RPi. Simply copy/paste these to the command line and HG will be up and running.
If the user has opted to connect a monitor and keyboard up, then they will have to type in those lines. I recommend using SSH as it makes life much simpler, but some people think a mouse will solve all problems so they want to have a GUI on the RPi. The problem with the older systems is that the RPi was not all that powerful and adding the GUI on top of things was a drawback. That hasn't been the case in years (since the RPi2 and 3 really).
If a user wants to install your image, they will save the steps of running a few commands on the command line, but then since the system is out of date, they will have to do the same by updating each package. I don't know if your installation has those packages linked back to the debian installer, but if not they will have to figure that out manually. If so, it's a matter of "sudo apt update && sudo apt upgrade".