Adding scikit-learn-intelex example

[ethanglaser]

Following up on #991 - in addition to updates to the documentation, it would be beneficial for users to see example usage of imbalanced-learn with scikit-learn-intelex imbalanced-learn to demonstrate usage and performance benefits.

I have prepared a notebook with some experiments, using examples taken from imbalanced-learn docs and the default hardware configuration on Google Colaboratory, comparing performance of scikit-learn and scikit-learn-intelex for several examples with smaller dataset configurations and a handful of examples using larger dataset configurations.

Would a more polished version of this notebook or something similar be of interest to include in imbalanced-learn examples? I see that most examples are .py scripts, but in this case it would be ideal to see a comparison of performance which is why a notebook was prepared, but am curious to hear what your preference would be here.

[ethanglaser]

Just following up here to see if this would be of interest