Returns a sorted character vector of the thematic categories present in
the demo.istat.it dataset registry. These categories can be passed to
list_demo_datasets for filtering.
Examples
# See all available categories
cats <- get_demo_categories()
print(cats)
#> [1] "dinamica" "indicatori" "matrimoni" "mortalita"
#> [5] "natalita" "popolazione" "previsioni" "unioni_civili"