clarify FAQ
clarify FAQ

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