docs/zh_CN: link the submit-checklist into process/index

That's helpful to let people find it in process/index.html.
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

@@ -36,6 +36,7 @@
    :maxdepth: 1
 
    submitting-drivers
+   submit-checklist
    stable-api-nonsense
    stable-kernel-rules