Update ssr-caching example with getServerSideProps (#11032)

* Replace getInitialProps by getServerSideProps

* Replace getServerSideProps getStaticProps

examples/ssr-caching/pages/blog/[id].js

@@ -0,0 +1,28 @@
+import React from 'react'
+
+export default function(props) {
+  return (
+    <div>
+      <h1>My {props.id} blog post</h1>
+      <p>
+        Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod
+        tempor incididunt ut labore et dolore magna aliqua.
+      </p>
+    </div>
+  )
+}
+
+export async function getStaticProps({ params: { id } }) {
+  return { props: { id } }
+}
+
+export async function getStaticPaths() {
+  return {
+    paths: [
+      { params: { id: 'first' } },
+      { params: { id: 'second' } },
+      { params: { id: 'last' } },
+    ],
+    fallback: true,
+  }
+}