Validate CRS units for sfc_to_cells

resolved in #6

sfdep::guerry$geometry |> sf::st_set_crs(27572) |> h3o::sfc_to_cells(4)
#> Error in `h3o::sfc_to_cells()`:
#> ! `x` must have a CRS using degrees such as EPSG:4326.
#> Backtrace:
#>     ▆
#>  1. └─h3o::sfc_to_cells(sf::st_set_crs(sfdep::guerry$geometry, 27572), 4)
#>  2.   └─rlang::abort("`x` must have a CRS using degrees such as EPSG:4326.") at h3o/R/sfc-to-cells.R:46:6

^{Created on 2023-09-06 with reprex v2.0.2}

JosiahParry / h3o

Validate CRS units for sfc_to_cells #5