Use vitejs instead of react-scripts

- react-scripts are not maintained anymore
- vitejs is well suited for single page applications

Fixes #335

See https://darekkay.com/blog/create-react-app-to-vite/

Change-Id: Ib884748e373094a640b576894ff67b98c3584ec8

vite.config.js

@@ -0,0 +1,6 @@
+import { defineConfig } from "vite";
+import react from "@vitejs/plugin-react";
+
+export default defineConfig({
+  plugins: [react()],
+});