Issue #3335159: hook_help function missing in .module file

term_glossary.module

@@ -10,7 +10,25 @@ use Drupal\Core\Field\FieldDefinitionInterface;
 use Drupal\Core\Field\FormatterInterface;
 use Drupal\Core\Form\FormStateInterface;
 use Drupal\taxonomy\Entity\Vocabulary;
+use Drupal\Core\Routing\RouteMatchInterface;
 
+/**
+ * Implements hook_help().
+ */
+function term_glossary_help($route_name, RouteMatchInterface $route_match) {
+  switch ($route_name) {
+    // Main module help for the term_glossary module.
+    case 'help.page.term_glossary':
+      $output = '';
+      $output .= '<h3>' . t('About') . '</h3>';
+      $output .= '<p>' . t('This flexible module uses a vocabulary (taxonomy) as a glossary.
+      It auto scans the fields (you configure it to) for uses of taxonomy terms
+      defined in your vocabulary.') . '</p>';
+      return $output;
+
+    default:
+  }
+}
 /**
  * Implements hook_theme().
  */