add ncl heat_index_nws outputs

[cyschneck]

Add heat_index_nws output values to use for heat_index in applications (NCAR/geocat-applications#124)

Output built from ncl script:

; heat_index_nws
; https://www.ncl.ucar.edu/Document/Functions/Contributed/heat_index_nws.shtml

; ncl -n heat_index_nws.ncl >> heat_index_nws_output.txt

print("Temperature (F), Relative Humidity (%), Heat Index (F)")
do tf=0,79
	do rh=1,40
		begin
		heatindex = heat_index_nws(tf,rh,(/2,2/), False)
		print (tf +","+ rh +","+ heatindex)
		end
	end do
end do

do tf=79,100
	do rh=40,100
		begin
		heatindex = heat_index_nws(tf,rh,(/2,2/), True)
		print (tf +","+ rh +","+ heatindex)
		end
	end do
end do