Add comment about improvment in comment v grepping

ex07/r_dwssap.sh

@@ -1,8 +1,13 @@
 #!/bin/sh
 
+# FT_LINE1=7
+# FT_LINE2=15
+
 FT_DIFF=$((FT_LINE2 - FT_LINE1 + 1))
 
 cat /etc/passwd |
+	# Not perfect, will discard line that contain a #
+	# anywhere in the line, not just the beginning
 	grep -v '#' |
 	sed '1d' |
 	awk 'NR % 2 == 1' |