feat: render document or fragment

templates/fragment/user/table.html

@@ -0,0 +1,7 @@
+<tr><th>name</th><th>email</th></tr>
+{% for user in users.as_ref().unwrap() %}
+<tr>
+    <td>{{ user.name }}</td>
+    <td>{{ user.email }}</td>
+</tr>
+{% endfor %}