GeoJSON to encoded polylines

[dcooley]

similar to how geojsonsf encodes GeoJSON - use the same 'geojson_to_` code, but at each iteration of extracting lon/lat, encode it into a polyline.

It would replace this workflow

library(geojsonsf)
library(googlePolylines)

googlePolylines::encode(
  geojsonsf::geojson_sf(geo_melbourne)
)