create_all_tif() produces tif files of all
crop distribution maps that are produced after the downscaling algorithm
is solved and the results are combined in one rds file using
combine_results(param). In theory, the function creates 320
maps: 2 (harvested area and physical area) x 40 (crops) x 4 (production
systems) but in practice the number will be lower, depending on the
actual number of crops and production systems observed in a country.