If you would rather not install the script yourself, here's a fully configured disk image that works with any Raspberry Pi: memorial_sh_v05.zip (540MB .zip file)
It's a ready-to run clone of an SD card, the "hard drive" that a Raspberry Pi boots from. I've taken all the necessary steps to properly install the memorial script, including setting it up as a system service.
Clone the disk image back to a fresh SD card, following i.e. these instructions. Then plug the Raspberry into your local Ethernet network. If you want it to show what it's doing, connect it to a screen, but that's optional. Then connect it to power, and leave it running. That's literally it.
The disk image is based on version v6.32 (31/08/2020) of DietPi, a stripped-down Linux distribution for the Raspberry. It's tested to run on all versions of the Raspberry Pi, including the 4.
Because the memorial script works using basic networking technology, I only had to install a few more required packages (avahi-daemon and git). The hostname is memorial, so use ping memorial or ping memorial.local to find out its IP address.
To see what's going on under the hood, feel free to log in with these details:
User pi
Password memorial
User root
Password memorial
Once up and running, make sure to change the password via sudo dietpi-config (the usual sudo passwd won't work persistently on DietPi ). Do this especially if you plan to keep it running for a long time.
The DietPi distribution comes with a few ways to easily set up Wifi. Log in with the above credentials, and use sudo dietpi-config to set up your connection.