Add unsupervised learning

talks/mardi/apprentissage_non-supervise.ipynb

talks/mardi/img01/gmm.png

talks/mardi/img01/manifold.png

talks/mardi/img01/matrix-representation.png

talks/mardi/img01/sampling_sphere.png

talks/mardi/img01/sklearn_logo.png

talks/mardi/img01/train-test-split.png

talks/mardi/img01/unsupervised-ml-workflow.png