It looks like seeedstudio now has a new version of that shield (v2 which is black as opposed to the one you linked to which is the red first version).
If it is really the red one you have, you've got yourself a tough problem: its driver chip (ST7781R) is not (yet) supported by notro's tft drivers (https://github.com/notro/fbtft/
), and even if it were, you'd need a lot of GPIO pins (12 if I'm not mistaken) because this module uses a parallel interface. Nothing impossible as far as I can see, but you'd need to write a driver or ask notro to do that and you'd pretty much be using all of your GPIO pins for it. I have no idea how efficient the end result would be.
The v2 has an SPI interface which is what most supported TFT modules have, and uses the ili9341 chip which is supported by notro's drivers.