Add page on regression / classification (#59)

* Add page on regression / classification

* route

* modif

* fix misspelling

* add missing link

* add one notebook

* fix missing reference

* fix a fex things

* add missing notebooks

* add more notebooks

* fix links

* fix link

* update links

* normalize

* fix urls

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Co-authored-by: xavier dupré <xavier.dupre@gmail.com>

Add plan (#38)