docs/zh_CN: link the license-rules file into process index

Make it appear in 'make htmldocs'
Signed-off-by: Alex Shi <alex.shi@linux.alibaba.com>
Cc: Harry Wei <harryxiyou@gmail.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: linux-doc@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

Documentation/translations/zh_CN/process/index.rst

@@ -27,6 +27,7 @@
    coding-style
    development-process
    email-clients
+   license-rules
 
 其它大多数开发人员感兴趣的社区指南：