🌐 [i18n-KO] Translated `contributing.md` to Korean (#25877)

* docs: ko-contributing.md

* feat: chatGPT draft

* feat: manual edits

* feat: change linked document

* fix: resolve suggestion
Co-authored-by: Haewon Kim <ehdvkf02@naver.com>

* fix: resolve suggestion
Co-authored-by: Haewon Kim <ehdvkf02@naver.com>

* fix: resolve suggestion
Co-authored-by: Haewon Kim <ehdvkf02@naver.com>

* fix: resolve suggestion
Co-authored-by: Haewon Kim <ehdvkf02@naver.com>

* fix: resolve suggestion
Co-authored-by: Haewon Kim <ehdvkf02@naver.com>

* fix: resolve suggestion
Co-authored-by: Haewon Kim <ehdvkf02@naver.com>

* fix: resolve suggestion
Co-authored-by: SeongWooChoi <46990061+nuatmochoi@users.noreply.github.com>

* fix: resolve suggestion
Co-authored-by: SeongWooChoi <46990061+nuatmochoi@users.noreply.github.com>

* fix: resolve suggestion
Co-authored-by: SeongWooChoi <46990061+nuatmochoi@users.noreply.github.com>

* fix: resolve suggestion

* fix: resolve suggestion

* feat: delete file to resolve error

---------
Co-authored-by: Haewon Kim <ehdvkf02@naver.com>
Co-authored-by: SeongWooChoi <46990061+nuatmochoi@users.noreply.github.com>

docs/source/ko/_toctree.yml

@@ -149,8 +149,8 @@
       title: TensorFlow 모델을 위한 XLA 통합
   title: (번역중) 성능 및 확장성
 - sections:
-    - local: in_translation
-      title: (번역중) How to contribute to transformers?
+    - local: contributing
+      title: 🤗 Transformers에 기여하는 방법
     - local: add_new_model
       title: 🤗 Transformers에 새로운 모델을 추가하는 방법 
     - local: add_tensorflow_model