You cannot (should not) have a figures folder in the main directory of your package.
I created a new file - README.Rmd. When you knit this file, it is converted into README.md with all images and code outputs presented.
Please edit this file (not the .md one).
I added (and renamed) the polygon dataset (see "inst/data/").
I added documentation files using the roxygen2 package.
I updated the DESCRIPTION file with several changes.
You can update your ORCID number there.
I added missing :: in several places.
I added the overall package helpfile - try ?rgugik.
My changes: