Rename demo.sh scripts to try.sh

This is because they are under the try section. I'm aware that there's a
script called try.me.sh but that's not been decided on a name change. It
probably should be changed to try.sh to be consistent and probably will
be but it's not been yet.

The manifest files in tmp/ have been updated as well, including the
macOS Numbers file.

1991/fine/README.md

@@ -19,7 +19,7 @@ echo text | ./fine
 ## Try:
 
 ```sh
-./demo.sh
+./try.sh
 ```
 
 Make sure that you read the last line backwards! Credit goes to [Merlyn LeRoy (Brian