Update index.md

Signed-off-by: Justin Kenyon <kenyonj@github.com>

Author: kenyonj

topics/hack-and-slash/index.md

@@ -2,7 +2,7 @@
 display_name: hack-and-slash
 topic: hack-and-slash
 aliases: hack-n-slash, hack-and-slash-game, hack-n-slash-game, hack-and-slay-game, hack-n-slay, hack-n-slay-game
-related: role-playing-game,mud, mmorpg
+related: role-playing-game, mud, mmorpg
 short_description: A genre of video game.
 wikipedia_url: https://en.wikipedia.org/wiki/Hack_and_slash
 ---