feat: Translate frontend/src/i18n/en.json in ko

90% of minimum 50% translated source file: 'frontend/src/i18n/en.json'
on 'ko'.

Sync of partially translated files: 
untranslated content is included with an empty translation 
or source language content depending on file format

frontend/src/i18n/ko.json

@@ -41,7 +41,7 @@
     "toggleSidebar": "사이드바 전환",
     "update": "업데이트",
     "upload": "업로드",
-    "openFile": "Open file",
+    "openFile": "파일 열기",
   "discardChanges": "Discard",
   "saveChanges": "Save changes"
   },