Air pollution tutorial should show path to "vectorization"

The air polution tutorial has a "vectorized" function to calculte the AIQ (IIRC). This can be vectorized using searchsorted (which is a bit much work, but not too tricky).
I am also almost completely certain that it can also be replaced with a single call to np.interp1d.

Having the "vectorize" version seems good, but doesn't fully leverage the concepts that NumPy provides. I think it would be great arc to keep it, but then also show the final interp and maybe even the searchsorted idea. (I honestly don't like stopping at vectorize becuzse it makes seems that vectorize is a common approach, when I consider it more of a fallback solution – whether used a lot in practice or not.)

Commencez par le tutoriel sur la pollution de l’air et localisez la fonction vectorisée existante utilisée pour calculer l’AQI. Comparez la manière dont le tutoriel pourrait présenter l’approche vectorize parallèlement aux idées de searchsorted et d’interpolation ; le travail est considéré comme terminé lorsque le tutoriel explique ces alternatives et ne laisse pas entendre que vectorize est la seule voie.