🌐 [i18n-KO] Translated model_doc/informer.md to Korean (#33585)

* docs: ko: model_doc/informer.md

* feat: nmt draft

* fix: manual edits

* fix: resolve suggestions

Co-authored-by: Ahnjj_DEV <ahnjj.dev@gmail.com>
Co-authored-by: HyeokJun SHIN <96534680+jun048098@users.noreply.github.com>

* fix: resolve suggestions

---------

Co-authored-by: Ahnjj_DEV <ahnjj.dev@gmail.com>
Co-authored-by: HyeokJun SHIN <96534680+jun048098@users.noreply.github.com>

docs/source/ko/_toctree.yml

@@ -761,8 +761,8 @@
       sections:
       - local: model_doc/autoformer
         title: Autoformer
-      - local: in_translation
-        title: (번역중) Informer
+      - local: model_doc/informer
+        title: Informer
       - local: model_doc/patchtsmixer
         title: PatchTSMixer
       - local: model_doc/time_series_transformer