Add Adrianne Marcum (@afmarcum) as a triager

[justaugustus]

@afmarcum has been instrumental in helping @ossf/scorecard-maintainers and @ossf/allstar-maintainers get organized.

Recent updates to default permissions within the OpenSSF GitHub org have removed her access. Let's restore that by granting her membership to @ossf/scorecard-triagers.

[jeffmendoza]

+1

[leec94]

+1

[justaugustus]

This is complete. Welcome to @ossf/scorecard-triagers, Adrianne (and thanks for all of your work)!