The silver ring below the black plastic secures the thermostat to the valve. If you loosen that screw, it will release pressure on the valve which in turn opens -> heating starts. It is rather tricky to fasten that ring again unless you can turn the thermostat to MAX though. Is the silver ring tight right now?
You could try out mediawiki (that’s the software Wikipedia is running on) on a local docket container on your machine to see if it actually is what you want or if you would prefer a simpler wiki software. Depending on how often you need it, you could self host on a raspberry pi in your home and make it accessible to your group through dyndns.