Issue 559: Update scan_grib to store levels with two surfaces#560

BjarkeMoholt wants to merge 5 commits intofsspec:mainfsspec/kerchunk:mainfrom

BjarkeMoholt:issue559_grib_store_vertical_levels_with_two_surfacesBjarkeMoholt/kerchunk:issue559_grib_store_vertical_levels_with_two_surfacesCopy head branch name to clipboard