Converting MNIST for fastai

@sgugger could you tell me how MNIST was converted for Fastai? I want to use FashionMNIST, KMNIST, and others like it to integrate it into Fastai like datasets.

What have I done: I downloaded kMNIST. Converted the arrays into images. Saved the images into folders (training/testing). Each folder contains a 10 folders: one per class of characters.

Is this the same that was done for MNIST?