Add menu translation for Chinese.

build.py

@@ -34,6 +34,7 @@ langs = [
     {"name": "Português", "ext": "pt-br"},
     {"name": "Türkçe", "ext": "tr"},
     {"name": "日本語", "ext": "jp"},
+    {"name": "简体中文", "ext": "zh-cn"},
 ]
 
 menu_translations = {
@@ -101,6 +102,17 @@ menu_translations = {
         "CREDITS": "Créditos",
         "SOURCE": "Código",
         "DONATE": "Ajude",
+    },
+    "zh-cn": {
+        "RETICULUM": "Reticulum",
+        "START": "开始使用",
+        "HARDWARE": "硬件要求",
+        "TESTNET": "测试网络",
+        "MANUAL": "阅读手册",
+        "CRYPTO": "密码学",
+        "CREDITS": "致谢",
+        "SOURCE": "源代码",
+        "DONATE": "支持开发",
     }
 }