Fixed an old mailing list link. (#166)

contributing/_answering-questions.md

@@ -2,9 +2,8 @@
 
 One of the most important and immediate ways you can support the community
 is to answer questions on the
-[forums](/community/#mailing-lists).
+[forums](/community/#forums).
 Whether you're helping a newcomer understand a language feature
 or troubleshooting an edge case with a seasoned developer,
 your knowledge and experience of Swift
 can go a long way to help others.
-