Ports system/game configuration location?

Hi all! I'm trying to make sense of how the Ports system in Retrobat works. When I go the roms folder, there are liberto files in there, but there doens't appear to be anything inside them? How does it know where the roms are for the three sample included games?

Which brings me to the next part of my question. There were some ports I had on the port section of the retropie menu (descent 2, Wolfenstein, etc). Can those be brought over? If so, what is the setup process? Looking at the retrobat wiki doesn't really tell me much.

Thanks!