Calculate JS divergence for historical sky maps
Calculate the Jenson-Shannon divergence between baseline and new sky maps for historical events.
The Jenson-Shannon divergence is the symmetrized Kullback-Leibler (KL) divergence computed using base 2 logarithms and divided by 2. It is symmetric and has a value between 0 (for identical distributions) and 1.
In this patch, we compute the divergence, but it is not yet added to the MkDocs output.