Add link to airflow metrics (#9425)
Add link to airflow metrics (#9425)

* Add link to airflow metrics

* Update airflow/README.md

Co-authored-by: Kari Halsted <6202b6c53ae98332d7db2799767b72058d728a62@users.noreply.github.com>

Co-authored-by: Kari Halsted <6202b6c53ae98332d7db2799767b72058d728a62@users.noreply.github.com>
DataDog/integrations-core,DataDog/integrations-core,DataDog/integrations-core,DataDog/integrations-core,DataDog/integrations-core,DataDog/integrations-core,DataDog/integrations-core,DataDog/integrations-core,DataDog/integrations-core,DataDog/integrations-core