Add info on past and present SG chairs (#1744)

* Add info on past and present SG chairs

* Update team.md

Author: eduardo-rodrigues

organization/team.md

@@ -43,3 +43,8 @@ case of multiple candidates, but can be by simple endorsement if there is only
 one candidate. In the case of a tie between candidates, the top two candidates
 are retained and a second round is held. If there is still a tie after the
 second round, the SG chair is decided by lot.
+
+## Present and Past SG Chairs
+
+- Eduardo Rodrigues (LHCb, University of Liverpool), 07/2025 -
+- Graeme Stewart (CERN EP-SFT), 07/2024 - 06/2025