feat(admin,admin-ui,medusa): Add Medusa Admin plugin (#3334)

packages/admin-ui/ui/src/main.tsx

@@ -0,0 +1,13 @@
+import ReactDOM from "react-dom/client"
+import "./assets/styles/global.css"
+import MedusaApp from "./medusa-app"
+
+async function run() {
+  const app = new MedusaApp()
+
+  ReactDOM.createRoot(document.getElementById("root") as HTMLElement).render(
+    app.render()
+  )
+}
+
+run()