Add String.join()

Author: zahar.kalosha

src/main/java/com/example/postgresdemo/service/QuestionService.java

@@ -51,7 +51,7 @@ public ResponseEntity<?> delete(Long questionId) {
     private QuestionResponseDTO toQuestionResponseDTO(Question question) {
         QuestionResponseDTO questionResponse = new QuestionResponseDTO();
         questionResponse.setId(question.getId());
-        questionResponse.setBody(question.getTitle() + "\n" + question.getDescription());
+        questionResponse.setBody(String.join("\n", question.getTitle(), question.getDescription()));
 
 
         return questionResponse;