Add Marc Alff in cpp-approvers (#1635)
Add Marc Alff in cpp-approvers (#1635)

* Add Marc Alff in cpp-approvers

Per discussion in C++ SIG Meeting, 2022-09-26.

* Order by name.

Co-authored-by: Tom Tan <5fc2d3cc368cf8e094b2bc925e7da57940ba5bc9@microsoft.com>
open-telemetry/opentelemetry-cpp,open-telemetry/opentelemetry-cpp,open-telemetry/opentelemetry-cpp,open-telemetry/opentelemetry-cpp