Add note about icon badge

- stateful component coming soon

schedules_web/src/components/Header.tsx

@@ -5,6 +5,7 @@ require('../css/iconbadge.css');
 
 const Header = () => (
     <div>
+        {/* TODO Extract into its own components with state management. */}
         <Row className="justify-content-end my-5 px-3">
             <span className="fa-stack fa-3x has-badge" data-count="0">
                 <i className="fa fas fa-shopping-bag fa-stack-1x" />