Request: additional tiles

[baslat]

Hello, thanks for making this package. I primarly use it via {ggspatial} for base layers. I would find it useful if there were a couple of additional tile styles available, namely no-label and only-label tiles for carto light. I think adding the following code to tileurl.R should do the trick; would you please consider adding it or accepting a PR for it? Thanks!

cartolight_nolabels = source_from_url_format(
	url_format = "http://a.basemaps.cartocdn.com/light_nolabels/${z}/${x}/${y}.png",
	attribution = "Map tiles by Carto, under CC BY 3.0. Data by OpenStreetMap, under ODbL."
  ),
cartolight_onlylabels = source_from_url_format(
	url_format = "http://a.basemaps.cartocdn.com/light_only_labels/${z}/${x}/${y}.png",
	attribution = "Map tiles by Carto, under CC BY 3.0. Data by OpenStreetMap, under ODbL."
)