add feed in / out button page and also button to redirect to button page

vite.config.ts

@@ -1,15 +1,48 @@
 /// <reference types="vitest/config" />
 import path from 'path';
+import type { Plugin } from 'vite';
 import { defineConfig } from 'vite';
 import react from '@vitejs/plugin-react';
 
+const buttonRoutePlugin = (): Plugin => ({
+  name: 'button-route',
+  configureServer(server) {
+    server.middlewares.use((req, res, next) => {
+      const url = req.url ?? '';
+      const [pathname, search = ''] = url.split('?');
+      const query = search ? `?${search}` : '';
+
+      if (pathname === '/button') {
+        res.statusCode = 301;
+        res.setHeader('Location', `/button/${query}`);
+        res.end();
+        return;
+      }
+
+      if (pathname === '/button/' || pathname === '/button/index.html') {
+        req.url = `/button/index.html${query}`;
+      }
+
+      next();
+    });
+  },
+});
+
 export default defineConfig({
-  plugins: [react()],
+  plugins: [react(), buttonRoutePlugin()],
   resolve: {
     alias: {
       '@': path.resolve(__dirname, '.'),
     },
   },
+  build: {
+    rollupOptions: {
+      input: {
+        main: path.resolve(__dirname, 'index.html'),
+        button: path.resolve(__dirname, 'button/index.html'),
+      },
+    },
+  },
   server: {
     port: 3001,
     host: '0.0.0.0',