Docs on API/staging

[mikesperber]

We need to documentation on the staging pipeline for actually compiling a model to TensorFlow/TF Lite, and running it.

Specifically, the process for providing sampling data and the format of the Args datatype are relevant here.

[tomsmeding]

We have written some documentation:

• Reference documentation on the API (as haddocks in the Data.Array.Accelerate.TensorFlow.Lite module);
• An example program here;
• A high-level technical overview of the implementation here.

For the time being, the rendered haddocks for the .Lite module can be found here: https://tomsmeding.com/f/acctflitedoc-2aca5833e/Data-Array-Accelerate-TensorFlow-Lite.html ; this link will stop working at some point, but for now it's there.

What do you think? Is there something missing?