to_netcdf docstring update
to_netcdf docstring update

shoyer/xray,pydata/xarray,jhamman/xarray,pydata/xarray,markelg/xray,chunweiyuan/xarray,kjordahl/xray,hetland/xray,shoyer/xarray,markelg/xray,hetland/xray,jhamman/xarray,NicWayand/xray,petercable/xray,markelg/xray,xray/xray,rabernat/xray,rabernat/xray,cpaulik/xray,jcmgray/xarray,jhamman/xarray,clarkfitzg/xray,cpaulik/xray,pydata/xarray,jhamman/xray,kjordahl/xray,drewokane/xray,clarkfitzg/xray,shoyer/xarray