Add some related topics

Author: leereilly

topics/hackathon/index.md

@@ -2,7 +2,7 @@
 topic: hackathon
 aliases: hackfest, codefest, hackday
 display_name: Hackathon
-related: game-jam
+related: game-jam, hacktoberfest, game-off
 short_description: A hackathon is a gathering where developers collaboratively code in an extreme manner over a short period of time.
 wikipedia_url: https://en.wikipedia.org/wiki/Hackathon
 ---