Issue #3404975 by Akhil Babu, joachim, smustgrave: Editor entity class should...

Issue #3404975 by Akhil Babu, joachim, smustgrave: Editor entity class should document that it expects a 1-1 relationship with matching IDs with a format entity

core/modules/editor/src/Entity/Editor.php

@@ -9,6 +9,11 @@
 /**
  * Defines the configured text editor entity.
  *
+ * An Editor entity is created when a filter format entity (Text format) is
+ * saved after selecting an editor plugin (eg: CKEditor). The ID of the
+ * Editor entity will be same as the ID of the filter format entity in which
+ * the editor plugin was selected.
+ *
  * @ConfigEntityType(
  *   id = "editor",
  *   label = @Translation("Text editor"),