[Update] Combine in one window. Rename Main/Config Window to Main/Config Page accordingly.

For now, I put Config Page to below the main page temporary. Open Config Button does not work.

src-ui/app/index.jsx

@@ -0,0 +1,12 @@
+import React from "react";
+import ReactDOM from "react-dom/client";
+import "@root/locales/config.js";
+import "@utils/root.css";
+
+import { App } from "./App";
+
+ReactDOM.createRoot(document.getElementById("root")).render(
+    <React.StrictMode>
+        <App />
+    </React.StrictMode>,
+);