docs/zh_CN: core-api: Add circular-buffers Chinese translation

docs/zh_CN: core-api: Add circular-buffers Chinese translation

Translate core-api/circular-buffers.rst into Chinese.

Last English version used:

commit 714b6904e23e ("doc: Remove ".vnet" from paulmck email addresses").

Signed-off-by: Binbin Zhou <zhoubinbin@loongson.cn>
Reviewed-by: Wu XiangCheng <bobwxc@email.cn>
Reviewed-by: Yanteng Si<siyanteng@loongson.cn>
Link: https://lore.kernel.org/r/6b94f233dd4b4a9e6da6fa2f86a9b1d32f104004.1660881950.git.zhoubinbin@loongson.cn
Signed-off-by: Jonathan Corbet <corbet@lwn.net>