Improve 2019/diels-grabsch/try.sh

Before doing 'diff -s sha512sum.txt prog.txt' it does a cat on both
files (in one command) so that one can see what is being compared
(or to verify what is being compared).

2019/diels-grabsch2/try.sh

@@ -36,6 +36,10 @@ elif [[ -n "$SHA512SUM" ]]; then
     ./prog > prog.txt
     echo 1>&2
 
+    echo "$ cat sha512sum.txt prog.txt" 1>&2
+    cat sha512sum.txt prog.txt
+    echo 1>&2
+
     echo "$ diff -s sha512sum.txt prog.txt" 1>&2
     diff -s sha512sum.txt prog.txt
     rm -f sha512sum prog.txt
@@ -56,6 +60,10 @@ elif [[ -n "$SHASUM" ]]; then
     ./prog > prog.txt
     echo 1>&2
 
+    echo "$ cat sha512sum.txt prog.txt" 1>&2
+    cat sha512sum.txt prog.txt
+    echo 1>&2
+
     echo "$ diff -s sha512sum.txt prog.txt" 1>&2
     diff -s sha512sum.txt prog.txt
     rm -f sha512sum prog.txt