Above the liquid markup, you need to have a YAML file header with the page's title, slug, and published flag, like this:
---
title: Page 2
slug: page2
published: true
---
{% extends 'index' %}
{% block 'main' %}This is the content for the page 2{% endblock %}
You can create files with such headers generated automatically by using the wagon generate page
command.
$ bundle exec wagon generate page test_page