Transform code base to typescript

Change-Id: Ia1f862fb5962ddd54b8d7643abbc39bb314d1f8e

src/index.tsx

@@ -0,0 +1,17 @@
+import React from "react";
+import { createRoot } from "react-dom/client";
+
+import App from "./App";
+import { AppContext } from "./AppContext";
+
+fetch("config.json")
+  .then(res => res.json())
+  .then(props =>
+    createRoot(document.getElementById("root")).render(
+      <React.StrictMode>
+        <AppContext.Provider value={props}>
+          <App />
+        </AppContext.Provider>
+      </React.StrictMode>
+    )
+  );