README edits
README edits

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