update README with API docs info
update README with API docs info

ministryofjustice/ds-auth,ministryofjustice/ds-auth,ministryofjustice/defence-request-service-auth,ministryofjustice/ds-auth,ministryofjustice/ds-auth,ministryofjustice/defence-request-service-auth,ministryofjustice/defence-request-service-auth,ministryofjustice/defence-request-service-auth