chore(playground): save `tsconfig.json` to the root directory; update Node.js version requirement (#9086)

Co-authored-by: Haoqun Jiang <haoqunjiang@gmail.com>

packages/sfc-playground/src/download/download.ts

@@ -27,7 +27,7 @@ export async function downloadProject(store: ReplStore) {
 
   const files = store.getFiles()
   for (const file in files) {
-    if (file !== 'import-map.json') {
+    if (file !== 'import-map.json' && file !== 'tsconfig.json') {
       src.file(file, files[file])
     } else {
       zip.file(file, files[file])

packages/sfc-playground/src/download/template/README.md

@@ -1,6 +1,6 @@
 # Vite Vue Starter
 
-This is a project template using [Vite](https://vitejs.dev/). It requires [Node.js](https://nodejs.org) v12+.
+This is a project template using [Vite](https://vitejs.dev/). It requires [Node.js](https://nodejs.org) version 18+, 20+.
 
 To start: