Add option to display the last update time on docs

Author: micalevisk

website/docusaurus.config.js

@@ -18,6 +18,7 @@ const siteConfig = {
           path: '../docs',
           routeBasePath: '/',
           sidebarPath: require.resolve('./sidebars.js'),
+          showLastUpdateTime: true,
           editUrl: 'https://github.com/reduxjs/react-redux/edit/master/website',
           include: [
             '{api,introduction,using-react-redux,tutorials}/*.{md,mdx}',