add bootstrap

src/App.js

@@ -5,10 +5,21 @@ import {
     Route,
     Link
   } from "react-router-dom";
+  import Card from 'react-bootstrap/Card'
   export default function App() {
     return (
       <Router>
         <div>
+        <Card style={{ width: '18rem' }}>
+  <Card.Body>
+    <Card.Title>Card Title</Card.Title>
+    <Card.Text>
+      Some quick example text to build on the card title and make up the bulk of
+      the card's content.
+    </Card.Text>
+
+  </Card.Body>
+</Card>
           {/* A <Switch> looks through its children <Route>s and
               renders the first one that matches the current URL. */}
           <Switch>