Update authors.yml

Co-authored-by: Stuart Montgomery <smontgomery@apple.com>

Author: ktoso

_data/authors.yml

@@ -570,7 +570,7 @@ stmontgomery:
   name: Stuart Montgomery
   email: smontgomery@apple.com
   github: stmontgomery
-  about: "Stuart works on Swift Testing at Apple."
+  about: "Stuart is a member of the Testing Workgroup and manages the Swift Testing Frameworks team at Apple."
 
 heckj:
   name: Joe Heck