Promote @mx-psi as approver

Fixes open-telemetry#2819

Signed-off-by: Bogdan Drutu <[email protected]>

Author: bogdandrutu

README.md

@@ -116,6 +116,7 @@ Approvers ([@open-telemetry/collector-approvers](https://github.com/orgs/open-te
 - [Anthony Mirabella](https://github.com/Aneurysm9), AWS
 - [Dmitrii Anoshin](https://github.com/dmitryax), Splunk
 - [Juraci Paixão Kröhling](https://github.com/jpkrohling), Grafana Labs
+- [Pablo Baeyens](https://github.com/mx-psi), DataDog
 
 Maintainers ([@open-telemetry/collector-maintainers](https://github.com/orgs/open-telemetry/teams/collector-maintainers)):