🚚(frontend) move previous app to mardownPDF app

We will start an monorepo archi, we move the previous
app to a new folder called mardownPDF.

src/frontend/apps/mardownPDF/vite.config.ts

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