Add Mobile Menu, slideout, styling and component restructure

src/components/SideMenu.js

@@ -0,0 +1,13 @@
+import React, { Component } from 'react'
+
+class SideMenu extends Component {
+  render() {
+    return (
+      <div className="side-menu">
+        <h1>Hello World</h1>
+      </div>
+    )
+  }
+}
+
+export default SideMenu