The datum grid package for PROJ contains shift grids for horizontal and vertical
coordinate transformations.

The PROJ-data package includes all grids and other resources previously tracked
by the proj-datumgrid series of packages as well as some new grids. All grids in
the PROJ-data package have been converted to the new Geodetic Tiff Grid (GTG)
format introduced in PROJ with RFC4.

WWW: https://github.com/OSGeo/PROJ-data
