[DOC] add new member to community page

Author: j143

_src/_data/contributors.yml

@@ -168,7 +168,7 @@
 - name: Olga Ovcharenko
   apacheId: oovcharenko
   githubId: OlgaOvcharenko
-  role: Committer
+  role: PMC Member
   org: TU Graz
 
 - name: Patrick Wendell