Add 1987/wall/try.sh

This script automates through a pipeline some of the input suggested in
the README.md. The README.md still has some of what try.sh has because
it shows that you can do it entering line by line.

1987/wall/README.md

@@ -19,22 +19,11 @@ make all
 ### Try:
 
 ```sh
-./wall | bc | ./wall
+./try.sh
 ```
 
-and input the following:
-
-```
-x*x
-c^2
-m*m
-
-# can you figure out what this does?
-500
-
-```
-
-You may also wish to try:
+You may of course run the commands manually and enter text as you wish. For
+instance you might try one or both of:
 
 ```sh
 ./wall | bc
@@ -50,6 +39,9 @@ x*x
 quit # for the cat version
 ```
 
+which the script does through a pipeline except that here you can enter more
+text if you wish, line by line.
+
 
 ## Judges' remarks: