use osmplotr for handy urban plots

[njtierney]

This could provide a useful default-ish / recommended plotting system:

https://cran.r-project.org/web/packages/osmplotr/vignettes/data-maps.html

[mpadge]

Even I've kinda gone off that these days in favour of mapview for the kinds of small-ish data sets used here. Sometimes, for better or worse, interactivity is soooo much more useful than beauty.

[njtierney]

I think it would be useful to provide some static and interactive plotting defaults, perhaps with names like:

• plot_mc_leaflet
• plot_mc_osmplot

Or something? Names are hard.