chore: set up routing with mock pages

src/router.tsx

@@ -0,0 +1,23 @@
+import { createBrowserRouter, RouterProvider } from "react-router-dom";
+import { Home } from "./pages/home";
+import { Podcast } from "./pages/podcast";
+import { Episode } from "./pages/episode";
+
+const router = createBrowserRouter([
+  {
+    path: "/",
+    element: <Home />,
+  },
+  {
+    path: "/podcast/:podcastId",
+    element: <Podcast />,
+  },
+  {
+    path: "/podcast/:podcastId/episode/:episodeId",
+    element: <Episode />,
+  },
+]);
+
+export function Router() {
+  return <RouterProvider router={router} />;
+}