A self-organizing map example

[automataIA]

You would like to see a new example being implemented by the Flax core team or the community? Please let us know by filling the following template.

1. A self-organizing map example(SOM Net, for unsupervised clustering )
2. image or data
3. use competitive learning rather than backpropagation
4. There are many examples on GitHub using python vanilla, but I need to work with images, with CPU and GPU optimization.