update v3.1.0

Test environments

local Ubuntu 20.04, R 4.3.0
local Windows 11, R 4.3.0
win-builder, devel, release & oldrelease - 1 NOTE regarding the spelling of 'shapefiles' in the DESCRIPTION, but the spelling is correct.
Github Actions, devel & release

R CMD check results

0 ERRORs, 0 WARNINGs, 0 NOTES