Added a section in the tutorial on how to find the min/max values and associated frequency.
Added a section in the tutorial on how to find the min/max values and associated frequency.

jhillairet/scikit-rf,temmeand/scikit-rf,temmeand/scikit-rf,jhillairet/scikit-rf,temmeand/scikit-rf,scikit-rf/scikit-rf,jhillairet/scikit-rf,scikit-rf/scikit-rf