initial support for pwa mode

vite.config.js

@@ -1,9 +1,14 @@
 import { defineConfig } from "vite";
+import { VitePWA } from 'vite-plugin-pwa';
+
 // import * as mdPlugin from 'vite-plugin-markdown';
 
 export default defineConfig(({ command, mode, ssrBuild }) => {
   if (command === "serve") {
     return {
+      plugins: [
+        VitePWA({ registerType: 'autoUpdate' })
+      ],
       assetsInclude: ["**/*.md"],
       server: {
         port: 8000,
@@ -12,6 +17,9 @@ export default defineConfig(({ command, mode, ssrBuild }) => {
     };
   } else {
     return {
+      plugins: [
+        VitePWA({ registerType: 'autoUpdate' })
+      ],
       chunkSizeWarningLimit: 1600 * 2,
       build: {
         outDir: "dist",