message: Add onDelete and onPreDelete descriptions
diff: @@ -67,7 +67,11 @@ fields, common to all data types:
  * `onSaveSuccess` Hook called when save is successful.
  -* `onPreSave` Hook called when saving fails.
  +* `onSaveFailure` Hook called when saving fails.
  +
  +* `onPreDelete` Hook called after the entity is deleted in Firestore. If you throw an error in this method the process stops, and an error snackbar gets displayed.
  +
  +* `onDelete` Hook called after the entity is deleted in Firestore.
  * `defaultValues` Object defining the initial values of the entity on creation.
  