Improve error message

Author: cpina

entrypoint.sh

@@ -34,7 +34,7 @@ mv "$CLONE_DIR/.git" "$TARGET_DIR"
 
 if [ ! -d "$SOURCE_DIRECTORY" ]
 then
-	echo "$SOURCE_DIRECTORY does not exist"
+	echo "ERROR: $SOURCE_DIRECTORY does not exist"
 	echo "This directory needs to exist when push-to-another-repository is executed"
 	echo
 	echo "In the example it is created by ./build.sh: https://github.com/cpina/push-to-another-repository-example/blob/main/.github/workflows/ci.yml#L19"