docs: add simplified code example and code embeds

content/blog/what-are-react-server-components/step1-code/index.html

@@ -0,0 +1,12 @@
+<main>
+  <button id="add-button">Count: 0</button>
+</main>
+<script>
+  let count = 0;
+
+  const addBtn = document.querySelector('#add-button');
+  addBtn.addEventListener('click', () => {
+    count++;
+    addBtn.innerText = `Count: ${count}`;
+  });
+</script>