Add Chinese language label

Author: tannewt

_includes/download/board.html

@@ -28,6 +28,8 @@ <h3>CircuitPython {{ version.version }}</h3>
                 ENGLISH
               {% when 'en_x_pirate' %}
                 PIRATE (ENGLISH)
+              {% when 'zh_Latn_pinyin' %}
+                CHINESE (PINYIN)
               {% when 'de_DE' %}
                 GERMAN
               {% when 'fil' %}