Auto generated sitemap.xml and indexed website content

[rogeriotaques]

Introduces:

• A simple sitemap.xml auto-generated from the content under pages
• An index for the entire website injected along with the site data that can be used in the page contents

Also, add site.config.js to the list of watched files, automatically reloading the page in the browser, when the file is updated without the need for a stop/start from the command line.