Docs/add nb for download

[jason-bentley]

PR

This PR creates copies of the tutorial notebooks and places them in a folder called notebooks. Please note the following:

1. Decided to leave transform_notebook.py where it is for now, in case we need all the options used previously. If it is decided that we no longer want the flexibility here and all we need is < 20-30 lines this could be consolidated into the make.py.
2. The downloaded notebooks are not populated with cell output. This is because we only commit without cell output.
3. For now, I have also omitted the two notebooks in sphinx/auxiliary – ideally, we would want to drop the getting started notebook in there, but two items need to be sorted out first:
   a. I don’t think we want to drop the notebook template in to notebooks as it is more of a developer thing
   b. Creating a link in the readme for downloading the getting started notebook will work there but not in the Sphinx documentation which just pulls in the readme.rst.

Insertion of links for notebook download in examples.rst will be added in a subsequent PR.

Run
To run please navigate to the sphinx folder and use python make.py html. Ensure that your copies of the notebooks in notebooks have been refreshed as part of the documentation build and that they do not contain the two cells for setting locations for facet, sklearndf and pytools or the matplotlib config cell as these are excluded based on cell metadata process by the transform_notebook.py. All other documentation should look the same.