feat: Replace nunjucks with new template and screen

- Replace ui index with liquid
- Add simple template inheriting from default

source/screens/demo/examples/ui/index.liquid

@@ -0,0 +1,24 @@
+---
+title: UI
+tags:
+- demoExample
+- index
+---
+{% layout "hippie/simple.liquid" %}
+
+{% block title %}{{ title }}{% endblock %}
+
+{% block body %}
+<div class="sec_main_center">
+	<nav role="doc-toc">
+		<h1>{{ title }}</h1>
+		<ul class="list_link">
+			{%- for ui in collections.ui -%}
+				<li>
+					<a href="{{ ui.page.url }}">{{ ui.data.title }}</a>
+				</li>
+			{%- endfor -%}
+		</ul>
+	</nav>
+</div>
+{% endblock %}