Implement better res default

[ChocopieKewpie]

Use a function to automatically define most suitable DGGS resolution-

i.e., calculate nearest dggs resolution to pixel.

[ChocopieKewpie]

See-
https://github.com/nmandery/rasterh3/blob/70c41a7cd42112f0470ff26b6fee8cd1758f8a5a/examples/h3ify_r_tiff.rs#L2

let h3_resolution = conv.nearest_h3_resolution(SmallerThanPixel).unwrap();