Update docs on defining Extra Operator links

[This doc](https://airflow.apache.org/docs/apache-airflow/stable/howto/define-extra-link.html) ([Code](https://github.com/apache/airflow/blob/main/airflow-core/docs/howto/define-extra-link.rst))  page needs to be updated for Airflow 3 related changes. Screenshot should also be updated.

This was updated in https://github.com/apache/airflow/pull/46613
