Revert "announcementBar"

This reverts commit e53a3b8.

Author: rubensdemelo

docusaurus.config.js

@@ -113,14 +113,6 @@ const config = {
         ],
         copyright: `Copyright © ${new Date().getFullYear()} Flutter Bootcamp`,
       },
-      announcementBar: {
-        id: 'lancamento',
-        content:
-          'Lançamento do Flutter Bootcamp! <a target="_blank" rel="noopener noreferrer" href="https://flutterbootcamp.com.br/">Saiba mais</a>',
-        backgroundColor: '#ffcc3d',
-        textColor: '#091E42',
-        isCloseable: false,
-      },
       prism: {
         theme: lightCodeTheme,
         darkTheme: darkCodeTheme,