Adding react-helmet and starting on a Layout component

src/components/Layout/index.js

@@ -0,0 +1,20 @@
+import React from 'react';
+import PropTypes from 'prop-types';
+import { Helmet } from 'react-helmet';
+
+const Layout = ({ title, children }) => <React.Fragment>
+  <Helmet>
+    <title>{ title ? `Regexper - ${ title }` : 'Regexper' }</title>
+  </Helmet>
+  { children }
+</React.Fragment>;
+
+Layout.propTypes = {
+  title: PropTypes.string,
+  children: PropTypes.oneOfType([
+    PropTypes.arrayOf(PropTypes.node),
+    PropTypes.node
+  ]).isRequired
+};
+
+export default Layout;

src/pages/index.js

@@ -1,5 +1,9 @@
 import React from 'react';
 
-const IndexPage = () => <div>Hello world</div>;
+import Layout from 'components/Layout';
+
+const IndexPage = () => <Layout>
+  <div>Hello world</div>
+</Layout>;
 
 export default IndexPage;