Using alpha and stroke of add_ground_bin to address intermixing of membership for binned figures

[boyiguo1]

As noted in the vignette Beyond Sequence-based Spatially-Resolved Data, the binning strategy proposed to address overplotting could lead to distorted interpretation due intermixing of data points within each bin.

A possible solution to address this is to display the proportion of majority membership within each bin using either transparency (alpha) or boundary size (stroke).