🌐 [i18n-KO] Translated perf_train_gpu_one.md to Korean (#39552)

* docs: ko: perf_train_gpu_one.md

* feat: nmt draft

* fix: manual edits

* fix: Manually added missing backticks

* Update docs/source/ko/perf_train_gpu_one.md

fix: remove space between heading and GPU anchor

Co-authored-by: YONGSANG <[email protected]>

* Update docs/source/ko/perf_train_gpu_one.md

fix: clarify table headers to indicate training speed boost and memory savings

Co-authored-by: YONGSANG <[email protected]>

* Update docs/source/ko/perf_train_gpu_one.md

fix: improve readability

Co-authored-by: Woojun Jung <[email protected]>

* Update docs/source/ko/perf_train_gpu_one.md

fix : rephrase explanation of data preloading to improve readability

Co-authored-by: Woojun Jung <[email protected]>

---------

Co-authored-by: YONGSANG <[email protected]>
Co-authored-by: Woojun Jung <[email protected]>

Author: 3 people

docs/source/ko/_toctree.yml

@@ -135,8 +135,8 @@
       title: 다중 GPU에서 학습 진행하기
     title: 분산 학습(Distributed training)
   - sections:
-    - local: in_translation
-      title: (번역중) GPU
+    - local: perf_train_gpu_one
+      title: GPU
     - local: perf_train_cpu
       title: CPU에서 훈련
     - local: perf_train_special