🌐 [i18n-KO] Translated `tasks_explained.mdx` to Korean (#23844)

* docs: ko: tasks_explained.mdx

* feat: nmt and manual edit `tasks_explained.mdx`

* revised: resolve suggestions task_explained.mdx

* fixed: added draft of reference docs
Co-Authored-By: Kihoon Son <75935546+KIHOON71@users.noreply.github.com>
Co-Authored-By: Nayeon Han <nayeon2.han@gmail.com>

* revised: resolve suggestions(voca, spell check) task_explained.mdx
Co-Authored-By: Sohyun Sim <96299403+sim-so@users.noreply.github.com>

* revised: remove duplicate sentence in task_explained.mdx

* fixed: remove draft of reference docs

- I think it will be confusing in the translation process.
- This issue is included in #23971.

---------
Co-authored-by: Kihoon Son <75935546+KIHOON71@users.noreply.github.com>
Co-authored-by: Nayeon Han <nayeon2.han@gmail.com>
Co-authored-by: Sohyun Sim <96299403+sim-so@users.noreply.github.com>

docs/source/ko/_toctree.yml

@@ -157,9 +157,9 @@
   - local: in_translation
     title: (번역중) Glossary
   - local: in_translation
-    title: (번역중) What 🤗 Transformers can do
-  - local: in_translation
-    title: (번역중) How 🤗 Transformers solve tasks
+    title: (번역중) 🤗 What 🤗 Transformers can do
+  - local: tasks_explained
+    title: 🤗 Transformers로 작업을 해결하는 방법
   - local: in_translation
     title: (번역중) The Transformer model family
   - local: in_translation