🌐 [i18n-KO] Translated tasks/question_answering.mdx to Korean (#23012)

docs: ko: `tasks/question_answering.mdx` to Korean

Co-authored-by: Hyeonseo Yun <0525yhs@gmail.com>
Co-authored-by: Sohyun Sim <96299403+sim-so@users.noreply.github.com>
Co-authored-by: Hyeonseo Yun <0525_hhgus@naver.com>
Co-authored-by: Gabriel Yang <gabrielwithhappy@gmail.com>
Co-authored-by: Kihoon Son <75935546+KIHOON71@users.noreply.github.com>

docs/source/ko/_toctree.yml

@@ -51,8 +51,8 @@
         title: 텍스트 분류
       - local: tasks/token_classification
         title: 토큰 분류
-      - local: in_translation
-        title: (번역중) Question answering
+      - local: tasks/question_answering
+        title: 질의 응답(Question Answering)
       - local: in_translation
         title: (번역중) Causal language modeling
       - local: tasks/masked_language_modeling