tldr: update Korean translation, common/t*: add Korean translation (#14645)

* common/t*: add Korean translation

* tldr: update Korean translation

* Update tcc.md

* Update pages.ko/common/tcc.md

Co-authored-by: Sebastiaan Speck <12570668+sebastiaanspeck@users.noreply.github.com>

* Update pages.ko/common/tar.md

Co-authored-by: Chooooo <contact@choo.ooo>

* Update pages.ko/common/tarsnap.md

Co-authored-by: Chooooo <contact@choo.ooo>

* Update pages.ko/common/tarsnap.md

Co-authored-by: Chooooo <contact@choo.ooo>

* Update pages.ko/common/transfersh.md

Co-authored-by: Chooooo <contact@choo.ooo>

* Update pages.ko/common/tuir.md

Co-authored-by: Chooooo <contact@choo.ooo>

* Update pages.ko/common/twine.md

Co-authored-by: Chooooo <contact@choo.ooo>

* Update pages.ko/common/twine.md

Co-authored-by: Chooooo <contact@choo.ooo>

---------

Co-authored-by: Sebastiaan Speck <12570668+sebastiaanspeck@users.noreply.github.com>
Co-authored-by: Chooooo <contact@choo.ooo>

pages.ko/common/termdown.md

@@ -0,0 +1,24 @@
+# termdown
+
+> 명령줄을 위한 카운트다운 타이머와 스톱워치.
+> 더 많은 정보: <https://github.com/trehn/termdown>.
+
+- 스톱워치 시작:
+
+`termdown`
+
+- 1분 30초 카운트다운 시작:
+
+`termdown {{1m30s}}`
+
+- 1분 30초 카운트다운을 시작하고 종료 시 터미널 깜빡이기:
+
+`termdown {{1m30s}} --blink`
+
+- 카운트다운 위에 제목 표시:
+
+`termdown {{1m30s}} --title "{{흥미로운 제목}}"`
+
+- 현재 시간 표시:
+
+`termdown --time`