Add 2000/natori/try.alt.sh + improve try.sh

The try.alt.sh script is slightly different from try.sh in that the
order is reversed.

The try.sh script now at the end always starts out in a sequence of
northern hemisphere then southern hemisphere so that one can guarantee
to get that form. The try.alt.sh does the same but starts out with the
southern hemisphere first.

2000/natori/try.sh

@@ -144,6 +144,17 @@ moon()
 	    ./"$NATORI.alt"; ./"$NATORI" ) | less -rEXF
     fi
     echo 1>&2
+
+    # Finally, for the try.sh (original entry, northern hemisphere), force
+    # starting with northern hemisphere.
+    echo "Will now use less(1): 'q' = quit, space = next page, enter = next line." 1>&2
+    echo "We now recommend that you try holding enter down." 1>&2
+    read -r -n 1 -p "Press any key to alternate between the northern/southern hemisphere Moon: "
+    echo 1>&2
+    ( ./"$NATORI"; ./"$NATORI.alt" ; ./"$NATORI" ; ./"$NATORI.alt"; \
+	./"$NATORI"; ./"$NATORI.alt" ) | less -rEXF
+
+    echo 1>&2
 }
 
 # show the Moon phase in artistic ways!