Add type field to Job entity.
function tmgmt_update_8003() {
$storage_definition = BaseFieldDefinition::create('list_string')
->setLabel(t('Job type'))
->setDescription(t('Type of job entity, can be Normal or Continuous.'))
->setSetting('allowed_values', [
Job::TYPE_NORMAL,
Job::TYPE_CONTINUOUS,
])
->setDefaultValue(Job::TYPE_NORMAL);
\Drupal::entityDefinitionUpdateManager()
->installFieldStorageDefinition('job_type', 'tmgmt_job', 'tmgmt', $storage_definition);
}