chore: update examples and Readme

examples/templates/example-simple.html

@@ -2,8 +2,7 @@
 <p>This is: {{this}}</p>
 <p>Custom field date: {{this.date}}</p>
 <ul>
-{%- for child, extras in this.children.items() -%}
-{%- set etxra = (extras|first).tags_in_page %}
-<li>{{etxra|length}} tags on page "{{child.path}}": {{etxra}}</li>
+{%- for child in this.children %}
+<li>page "{{child.path}}" with tags: {{child.tags}}</li>
 {%- endfor %}
 </ul>