docs/zh_CN: Add coding-style into docs build system

Tested by the command:

    make htmldocs

During the compiling process, zh_CN/coding-style.rst has no errors and
warnings generated, the generated html document has been checked.

Signed-off-by: Andy Deng <theandy.deng@gmail.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
diff --git a/Documentation/index.rst b/Documentation/index.rst
index cb5d776..f6e641a 100644
--- a/Documentation/index.rst
+++ b/Documentation/index.rst
@@ -47,7 +47,7 @@
 from the point of view of a kernel developer.  Much of the information here
 is taken directly from the kernel source, with supplemental material added
 as needed (or at least as we managed to add it — probably *not* all that is
-needed). 
+needed).
 
 .. toctree::
    :maxdepth: 2
@@ -68,6 +68,14 @@
 
    translations/ko_KR/index
 
+Chinese translations
+--------------------
+
+.. toctree::
+   :maxdepth: 1
+
+   translations/zh_CN/index
+
 Indices and tables
 ==================