feat(Container): Add new css customization

CSS for the central alignment of the header is now isolated, so it must be loaded here

Author: alanbueno

src/components/Container.react.js

@@ -3,6 +3,8 @@
 import * as React from "react";
 import cn from "classnames";
 
+import "./Container.css";
+
 type Props = {|
   +children?: React.Node,
   +className?: string,