Contributing code from NDArray

[cgarciae]

I made this library called NDArray a while ago and got it to a POC state. I know ShapedArray is on the radar so I wanted to know if I could contribute the code to a longer term project.

[dan-zheng]

For reference: other n-d array implementations exist at tensorflow/swift-apis. That library currently provides two n-d array types:

• ShapedArray: a Collection-conforming n-d array, following standard techniques to implement shaping, indexing, and slicing.
• Tensor: an accelerable n-d array defining all math-y operations. Has the potential to support multiple backends.

I would love to see the community combine efforts to develop the best (most idiomatic) APIs, since there aren't Swift naming conventions for numerical computing yet.