Localhost site admins should not be prompted to register their site

When someone installs Moodle, the message 'Your site is not yet registered.' and button 'Register your site' is very prominent. Many people don't realise that they can't register a locally installed site, and don't understand the error message which is displayed when they attempt to do so. A common confusion is thinking that registering the site makes it available for students to access!

Every day, many people email support@moodle.org saying that they can't register their locally installed site. It would be great instead if Moodle could detect localhost sites and not display the prompt to register the site. We could instead display some text explaining what to do to make the site available for students to access (follow the documentation for installing Moodle online or sign up for a MoodleCloud site etc.).