Add 1990/theorem/try.sh

This script shows not just theorem but the sorter and the Fibonacci
generator as well. For the sorter it reverses output of ls (redirected
to a file) and then shows how using sorter on it results in the same
output of ls (with no options specified). Of course if different ls
sorts output differently this could fail but I did not think of that
until after I wrote it.

1990/theorem/README.md

@@ -36,20 +36,10 @@ y1 - initial value  (y(x1) == y1)
 ### Try:
 
 ```sh
-./theorem y 0 1 0.1 1
+./try.sh
 ```
 
-If the two args passed to `fibonacci` and `theorem_bkp` add to 0 it will
-print 0 over and over again in an infinite loop. In this case it should not be
-fixed (another condition where this occurred was fixed in 2023 as it affected
-usability of the program).
 
-This is supposed to happen.  As is written in the
-[The Jargon File](http://catb.org/jargon/html/F/feature.html):
-
-```
-That's not a bug, that's a feature.
-```
 
 
 ## Judges' remarks:
@@ -113,6 +103,11 @@ make fibonacci
 ./fibonacci 2 1
 ```
 
+NOTE: if the two args passed to `fibonacci` and `theorem_bkp` add to 0 it will
+print 0 over and over again in an infinite loop. In this case it should not be
+fixed (another condition where this occurred was fixed in 2023 as it affected
+usability of the program).
+
 Program available on 9 track and cartridge cassette.  Neither [Ginsu
 knife](https://ginsu.com) nor [Swiss army
 knife](https://en.wikipedia.org/wiki/Swiss_Army_knife) included! :-)