You're missing out on some unique documentation if you don't check out the readme: https://github.com/vladocar/60gs
Why do people keep making CSS grid frameworks? The whole point of grid is that you no longer need boilerplate grid libs...
This is not a framework though, just CSS Grid :)
So why add another dependency? Just doesn't make sense to me. Grid makes it so easy to define your own layout which makes things like this seem redundant.
This solution is can be used for everything even for Photoshop or Grid on Paper. You split the grid with 60 grid units and because 60 is first number dividable by 2,3,4,5 and 6 you can make 1 to 6 columns. This is just Grid System and you can use it for making any grid on any medium.
The point of grid is to also apply semantic naming to your grid areas. This increases code readability and understanding. Here is a good read for the uninitiated: