fix: 💚 GH actions: bugfix and add error handling

.github/scripts/extract-refstyle-badges/extract-refstyle-badges.sh

@@ -8,9 +8,31 @@
 #
 # #################################################################################
 
+# ===== Error handling =======
+# set -e: exit on error
+set -e
+
+# invoke the catch() function whenever an error occurs
+trap 'catch $? $LINENO' EXIT
+
+# catch() function just prints an error message (before exit)
+catch() {
+  if [ "$1" != "0" ]; then
+    # error handling goes here
+    echo "    (Exiting due to return code $1 on line $2)" >&2
+  else
+    echo "Script completed successfully"
+  fi
+}
+
+
 # get a reference to the current directory
 DIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" >/dev/null 2>&1 && pwd )"
+# relative path to README.md
 READMEFILE="${DIR}/../../../README.md"
+# temporary file
+TEMPFILE="${DIR}/md-badges.md"
+# relative path to output file
 OUTFILE="${DIR}/../../../docs/REFERENCE_STYLE.md"
 
 # extract the table rows from README.md, sort them, and pass them to 
@@ -22,10 +44,10 @@ readmerows=$(
   sort 
 )
 
-# add a newline before processing with awk
+# add a newline before processing with awk into TEMPFILE
 printf "%s\n\n" "$readmerows" \
   | gawk --posix -F '|' -f "${DIR}/extract-refstyle-badges.awk" \
-> "${DIR}/md-badges.md"
+> "${TEMPFILE}"
 
 # now insert the generated md-badges.md content into README.md
 
@@ -35,7 +57,7 @@ tail='^<\!-- ### END GENERATED CONTENT -->'
 sed -e "/$lead/,/$tail/{
   /$lead/{
     p;
-    r $DIR/md-badges.md
+    r $TEMPFILE
   };
   /$tail/p;
   d