@darknior I don't think our script is what you need then. You might want to look into Skyscraper that muldjord is working on. I can't remember if he ever added the ability to use our synopsis or not, but he was willing to do it.
The script that meleu's been tweaking does it all. There's no way to just convert the synopsis.txt files to xml files with it. Even if there were, I don't know how this would save you any time.
I'm afraid that you're going to end up spending tons of time making xml files that you don't need to. It really doesn't take that long to follow the instructions and set up your media correctly. You can then run the script and let the pi make every gamelist.xml for every system that it currently handles. It would take about 16 hours on a Pi Zero and would probably be much quicker on a Pi 3.
Not bad, considering if I were to do it all by hand it would probably take me 2 or 3 thousand hours to write them.
It's up to you though. :)