finishes functionality for cart, checkout, return and renter registration

bookish-ui/src/App.tsx

@@ -1,8 +1,11 @@
-import React from 'react';
+import React, { useEffect } from 'react';
 import './App.css';
 import styled from 'styled-components';
 import Sidebar from './containers/Sidebar/Sidebar';
 import Content from './containers/Content/Content';
+import { useDispatch } from 'react-redux';
+import { fetchBooks } from './actions/books';
+import { fetchRenters } from './actions/renters';
 
 const AppContainer = styled.div`
     background: #13334A;
@@ -10,11 +13,20 @@ const AppContainer = styled.div`
     display: flex;
 `
 
-const App: React.FC = () => (
+const App: React.FC = () => {
+  const dispatch = useDispatch();
+
+  useEffect(() => {
+    dispatch(fetchBooks());
+    dispatch(fetchRenters());
+  }, []);
+  
+  return (
     <AppContainer>
       <Sidebar/>
       <Content />
     </AppContainer>
-)
+  );
+};
 
 export default App;