Issue #2862746 by masipila, quietone, phenaproxima: Add documentation to...

Issue #2862746 by masipila, quietone, phenaproxima: Add documentation to EntityFieldStorageConfig destination plugin

core/modules/migrate/src/Plugin/migrate/destination/EntityFieldStorageConfig.php

@@ -3,7 +3,48 @@
 namespace Drupal\migrate\Plugin\migrate\destination;
 
 /**
- * Provides entity field storage configuration plugin.
+ * Provides destination plugin for field_storage_config configuration entities.
+ *
+ * The Field API defines two primary data structures, FieldStorage and Field.
+ * A FieldStorage defines a particular type of data that can be attached to
+ * entities as a Field instance.
+ *
+ * The example below creates a storage for a simple text field. The example uses
+ * the EmptySource source plugin and constant source values for the sake of
+ * simplicity.
+ * @code
+ * id: field_storage_example
+ * label: Field storage example
+ * source:
+ * plugin: empty
+ * constants:
+ *   entity_type: node
+ *   id: node.field_text_example
+ *   field_name: field_text_example
+ *   type: string
+ *   cardinality: 1
+ *   settings:
+ *     max_length: 10
+ *   langcode: en
+ *   translatable: true
+ * process:
+ *   entity_type: constants/entity_type
+ *   id: constants/id
+ *   field_name: constants/field_name
+ *   type: constants/type
+ *   cardinality: constants/cardinality
+ *   settings: constants/settings
+ *   langcode: constants/langcode
+ *   translatable: constants/translatable
+ * destination:
+ *   plugin: entity:field_storage_config
+ * @endcode
+ *
+ * For a full list of the properties of a FieldStorage configuration entity,
+ * refer to \Drupal\field\Entity\FieldStorageConfig.
+ *
+ * For an example on how to migrate a Field instance of this FieldStorage,
+ * refer to \Drupal\migrate\Plugin\migrate\destination\EntityFieldInstance.
  *
  * @MigrateDestination(
  *   id = "entity:field_storage_config"