docs/kokr: Link memory-barriers.txt to rst

This commit links Korean translation of 'memory-barriers.txt' in the
translations index rst file as the original version is linked in
'Documentation/staging/index.rst'.
Signed-off-by: NSeongJae Park <sjpark@amazon.de>
Link: https://lore.kernel.org/r/20210117100931.9347-4-sj38.park@gmail.comSigned-off-by: NJonathan Corbet <corbet@lwn.net>

Documentation/translations/ko_KR/index.rst

@@ -10,3 +10,18 @@
    :maxdepth: 1
 
    howto
+
+
+리눅스 커널 메모리 배리어
+-------------------------
+
+.. raw:: latex
+
+    \footnotesize
+
+.. include:: ./memory-barriers.txt
+    :literal:
+
+.. raw:: latex
+
+    \normalsize