[site] Fix index.md to point to zh_CN

Author: hazendaz

src/site/ko/markdown/index.md

@@ -27,7 +27,7 @@ author: Clinton Begin, 이동국(한국어 번역)
 <!--      <li class="fr"><a href="../fr/index.html">프랑스어</a></li> -->
           <li class="ja"><a href="../ja/index.html">일본어</a></li>
           <li class="ko"><a href="../ko/index.html">한국어</a></li>
-          <li class="zh"><a href="../zh/index.html">중국어번체</a></li>
+          <li class="zh"><a href="../zh_CN/index.html">중국어번체</a></li>
 </ul>
 
 당신의 모국어로 작성된 마이바티스 문서를 읽고 싶은가? 그렇다면 모국어로 작성된 문서를 패치로 첨부한 이슈를 등록해달라!

src/site/markdown/index.md

@@ -27,7 +27,7 @@ Users can read about MyBatis in following translations:
 <!--      <li class="fr"><a href="./fr/index.html">Français</a></li> -->
           <li class="ja"><a href="./ja/index.html">日本語</a></li>
           <li class="ko"><a href="./ko/index.html">한국어</a></li>
-          <li class="zh"><a href="./zh/index.html">简体中文</a></li>
+          <li class="zh"><a href="./zh_CN/index.html">简体中文</a></li>
 </ul>
 
 Do you want to read about MyBatis in your own native language? File an issue providing patches with your mother tongue documentation!

src/site/zh_CN/markdown/index.md

@@ -25,7 +25,7 @@ MyBatis 是一款优秀的持久层框架，它支持自定义 SQL、存储过
           <!--      <li class="fr"><a href="./fr/index.html">Français</a></li> -->
           <li class="ja"><a href="../ja/index.html">日本語</a></li>
           <li class="ko"><a href="../ko/index.html">한국어</a></li>
-          <li class="zh"><a href="./getting-started.html">简体中文</a></li>
+          <li class="zh"><a href="../zh_CN/getting-started.html">简体中文</a></li>
 </ul>
 
 想用你的母语来了解 MyBatis 吗？那就将文档翻译成你的母语并提供给我们吧！