Revert "Remove Chinese translation since it 404s."

This reverts commit 8bb35313b1.

This is no longer needed.

site/_data/translations.yml

@@ -8,6 +8,11 @@
   description: Bootstrap 4 · 全球最流行的 HTML、CSS 和 JS 工具库。
   url: https://code.z01.com/v4
 
+- name: Chinese
+  code: zh
+  description: Bootstrap 4 中文文档教程
+  url: https://wiki.jikexueyuan.com/project/bootstrap4/
+
 - name: Brazilian Portuguese
   code: pt-BR
   description: Bootstrap 4 Português do Brasil