Trying to set
Allowed number of values always to be 1 and not allowing multiple values for a custom Drupal 8 field.
How to do that?
Do I need a form_ID_alter or a storageSettingsForm/defaultStorageSettings implementation?
I see this field is not included in the storageSettingsForm
Not sure if the best way is to set it as configuration or alter the form. Is there an annotation for this or something? Any example module that does this?