docs: layout add showcase link

Author: wpxp123456

app/layout.config.tsx

@@ -26,6 +26,10 @@ export function baseOptions(locale: string): BaseLayoutProps {
         text: customTranslations[locale]['icons.title'],
         url: '/icons',
       },
+      {
+        text: customTranslations[locale]['showcase.title'],
+        url: '/showcase',
+      },
       {
         type: 'custom',
         children: (