Build bilingual Astro exchange landing page and brand reference

astro.config.mjs

@@ -0,0 +1,6 @@
+import { defineConfig } from 'astro/config';
+export default defineConfig({
+  site: 'https://sxchnge.muddy-nova-7708.chatgpt.site',
+  output: 'static',
+  trailingSlash: 'always',
+});