0.1 accuracy on MNIST fashion dataset following official Tensorflow/Keras tutorial
You haven't normalized your image dataset such as setting the pixel values between 0-1 which could help classifier converge faster.

Please do it by doing the operation below.

train_images = train_images / 255.0

test_images = test_images / 255.0


It seems you are using 50% of data for training as well as testing.
try to use the data in the ratio of 7:3 for training and testing.
Increase the epochs hope it will work.