Build v0 example and SSE slices

examples/v0/templates/todos.heml

@@ -0,0 +1,11 @@
+<section data-slhx-root="todos">
+  <form data-slhx-handle="add_todo" data-slhx-form="new_todo">
+    <input name="title" required="required">
+    <button type="submit">Add</button>
+  </form>
+  <ul data-slhx-slot="todo_list">
+    <template h-for="todo in &self.todos" h-key="todo.id">
+      <li data-slhx-slot="todo_row">{+ todo.title +}</li>
+    </template>
+  </ul>
+</section>