Awesome! Just the tool I needed. I am developing my own board game and the hustle to create the cards to print and test was getting in the way of actually thinking about the game and the rules.
A small suggestion: add a image-top and a image-bottom fields where you put a URL and the PDF includes the image on the card.
If you want a more featureful tool, but still data-oriented and built with a programming-slant, I highly recommend Squib[1]. It has tons of rendering and processing options, and fairly thorough documentation (unlike pretty much everything else out there).
A small suggestion: add a image-top and a image-bottom fields where you put a URL and the PDF includes the image on the card.