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.)

从空气污染教程开始，找到现有的用于计算 AQI 的向量化函数。比较教程如何将 vectorize 方法与 searchsorted 和插值的思路并列介绍；当教程解释了这些替代方案，且没有暗示 vectorize 是唯一途径时，即视为完成。