alpha 1

• First version
• exchanging via JSON format
• lightweight format (structure: json, arrays: URI)
• numpy.dtype supported: all except 'complex' and 'timedelta'
• NTVtype supported:
  • datetime, date, time, dat
  • month, year, day, wday, yday, week, hour, minute, second
  • json, string, number, boolean, array, object, null
  • floatxx, uintxx, intxx
  • base16, decimal
  • uri, ipv4, email, file
  • point, line, polygon, geometry, geojson
  • multipoint, multiline, multipolygon, box, codeolc
  • ndarray, xndarray, field, tab, ntv
• interface:
  • astropy.NDData
  • scipp.Dataset
  • Xarray.Dataset, Xarray.Dataarray
  • JSON