Leaflet maps encode data directly into the HTML pages using the R package

[pauldpickell]

Leaflet maps created using the R leaflet package encode the json and geojson data directly into the built html pages. This causes some chapter html files like /docs/raster-analysis-and-terrain-modelling.html to be very heavy (74 MB) and take a long time to load.

Need to think about what the fix is here.

Do we need to manually configure these leaflet maps to properly reference the resources in /data/?

Do we make the leaflets separate html pages and convert the existing maps to static images for the chapter html pages with a URL to the leaflet in the figure caption?

May also need to implement lazy loading on some of these content heavy chapters.