How to use / run this project ? what is is it ?

This is certainly the most stupid question you will have, but i just got access to this repository and wonder what it was. This is RPG, well but how to run anything, what is the starting point ? Quickly looking at https://www.faterpg.com/ didn't help me that much, not sure if it online thing, if there is a binary to run on the system or if result is .. a pdf ? I may have my answer by digging a little more, but 5 minutes were not enough yet...