[#814,tutorial,docs][xl]: add initial version of the second tutorial, rename basic-example to learn-example, clean up learn-example

examples/learn-example/lib/loadData.tsx

@@ -0,0 +1,5 @@
+export default async function loadData(url: string) {
+  const response = await fetch(url)
+  const data = await response.text()
+  return data
+}