<?php

use Drupal\node\Entity\NodeType;

function riverside_pt_install() {
   $type = NodeType::create([
      'type' => 'appointment',
      'name' => 'Appointment',
      'description' => 'A booking between a Patient and a Provider at a particular time.',
      'new_revision' => FALSE,
      'preview_mode' => DRUPAL_DISABLED,
      'display_submitted' => FALSE,
   ]);
   $type->save();
}