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.)

Beginne mit dem Tutorial zur Luftverschmutzung und finde die vorhandene vektorisierte Funktion, die zur Berechnung des AQI verwendet wird. Vergleiche, wie das Tutorial den vectorize-Ansatz neben den Ideen von searchsorted und Interpolation darstellen könnte; abgeschlossen ist die Aufgabe, wenn das Tutorial diese Alternativen erklärt und nicht den Eindruck vermittelt, vectorize sei der einzige Weg.