Issue #3341853: Implement hook_help()

Closes #3341853

ui_patterns_field_formatters.module

@@ -5,6 +5,22 @@
  * UI Patterns Field Formatters module.
  */
 
+use Drupal\Core\Routing\RouteMatchInterface;
+
+
+/**
+ * Implements hook_help().
+ */
+function ui_patterns_field_formatters_help($route_name, RouteMatchInterface $arg) {
+  switch ($route_name) {
+    case 'help.page.ui_patterns_field_formatters':
+      $output = '';
+      $output .= '<h3>' . t('About') . '</h3>';
+      $output .= '<p>' . t('The UI Patterns Field Formatters module exposes components from UI Patterns to the Field Formatter API.') . '</p>';
+      return $output;
+  }
+}
+
 /**
  * Implements hook_field_formatter_info_alter().
  */