Map zh_cn to zh-CN please

Map zh_cn to zh-CN please

د Zhigang Sun لخوا -
د ځوابونو شمیر: 2
د Language pack maintainers انځور

Hi, David

I checked that the code of Simplified Chinese in google translate is zh-CN and zh_cn in moodle. So please add the map in AMOS so that we can do translation work easier and better.

Thank you!

Sunner