Nelson

Nelson is a little *lifehack* IoT module that has been created by Maxime Castelli for the "Fabriquer un objet connecté" MOOC (the second version of `nelson_top.stl` and `nelson_bottom_v2.stl` have been made by [Paolo Merlhiot](https://www.thingiverse.com/PaoloElMarinelo/about))