That' Help and documentation' link is what used to be "Moodle docs for this page" link that appears at the footer of every Moodle page if you have editing rights to it. So a student didn't see that link and doesnt see this link, since they do not edit the page and need help from the user documentation.
The 'contact site support' link is set by the admin from https://YOURMOODLESITE/admin/settings.php?section=supportcontact