fix/263 performance regression (#264)

* Replace deep copies in Component.render
* Add 2nd example component to sampleproject

sampleproject/components/calendar/calendar.html

@@ -1 +1,13 @@
-<div class="calendar-component">Today's date is <span>{{ date }}</span></div>
+<div class="calendar-component">
+  <div>Today's date is <span>{{ date }}</span></div>
+  <div>Your to-dos:</div>
+  <ul>
+    <li>
+      {% component_block "todo" %}
+        {% fill "todo_text" %}
+          Stop forgetting the milk!
+        {% endfill %}
+      {% endcomponent_block %}
+    </li>
+  </ul>
+</div>

sampleproject/components/todo/todo.html

@@ -0,0 +1,4 @@
+<div class="todo-item">
+  {% slot "todo_text" %}
+  {% endslot %}
+</div>

sampleproject/components/todo/todo.py

@@ -0,0 +1,9 @@
+from django_components import component
+
+
+@component.register("todo")
+class Calendar(component.Component):
+    # Note that Django will look for templates inside `[your apps]/components` dir and
+    # `[project root]/components` dir. To customize which template to use based on context
+    # you can override def get_template_name() instead of specifying the below variable.
+    template_name = "todo/todo.html"