Added core site pages

Property	Value
description	Added the shipped core site-page set and assigned the static homepage.

• Added the core public page set: Home, About, and Contact.
• Created the Home page with the home slug and assigned it as the static front page at /.
• Created the About page with the about slug at /about.
• Created the Contact page with the contact slug at /contact.
• Left the posts page unassigned so the site does not ship with a blog index page selected by default.