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/README.md

@@ -22,6 +22,9 @@ version](#alternate-code) below.
 ./try.sh
 ```
 
+Try running this on different days, say a few days apart, and each time run it
+several times in a row (or several times in a day).
+
 Also try modifying the code so that it will show another Moon phase based on
 input or else just by the code itself. Bonus points if you can make it show all~
 
@@ -47,6 +50,9 @@ make alt
 ./natori.alt
 ```
 
+Try running this on different days, say a few days apart, and each time run it
+several times in a row (or several times in a day).
+
 What happens if you run it in the northern hemisphere? Are there any
 differences?
 
@@ -54,6 +60,15 @@ Can you identify any Moon phases that result in the same output of both
 versions? Or are there any?
 
 
+### Alternate try:
+
+```sh
+./try.alt.sh
+```
+
+Like with [try.sh](try.sh), try using this multiple times.
+
+
 ## Judges' remarks:
 
 Here is a nice compact program that changes with the phase of the Moon.