Add Suspense import hint. (#22)

For those not familiar with Suspense, they may not know where Suspense is supposed to come from.

Author: seantomburke

exercises/02.server-components/03.problem.streaming/ui/app.js

@@ -1,4 +1,5 @@
-import { Fragment, createElement as h } from 'react'
+// 🐨 you'll want to import Suspense from react
+import { /* Suspense */, Fragment, createElement as h } from 'react'
 import {
 	ShipDetails,
 	// 💰 you'll want this: