Fix typo (umijs#4267)

SIvaCoHan · web-flow · commit 8203a9190487 · 2020-03-25T11:37:33.000+08:00
问题：config配置中layout 配置字典以分号作为分割符
解决：将分号改为逗号，已修复。
diff --git a/docs/plugins/plugin-layout.zh-CN.md b/docs/plugins/plugin-layout.zh-CN.md
@@ -26,8 +26,8 @@ import { defineConfig } from 'umi';
 
 export const config = defineConfig({
   layout:{
-    name: 'Ant Design'; 
-    locale: true;
+    name: 'Ant Design', 
+    locale: true,
   }
 });
 ```
