Create Figure Protected Areas script

[jcoliver]

Old location and name: src/summary/protected-areas-4-plot-hotspots.R
New location and name: src/manuscript/figs-5-protected.R

Script should include supplemental figures, too; current script (protected areas-4...) currently focuses only on the one figure to be included in the main manuscript.

Main: Area and proportion (or %?) of range on protected lands for SSP3-7.0 for all three time points
Supplemental: Area and proportion (%) of range on protected lands for remaining SSPs