feat: added file index.js

react-config-tutorial/src/index.js

@@ -0,0 +1,11 @@
+import React from "react";
+import ReactDOM from "react-dom";
+/*
+ *component Welcome
+ */
+class Welcome extends React.Component {
+  render() {
+      return <h1>react-config-tutorial</h1>;
+  }
+}
+ReactDOM.render(<Welcome />, document.getElementById("root"));