[topics/game-development] Add 'gamedev' as alias

"gamedev" has 6,000+ repositories, some 25-35% of "game-development" having 19,000+

Author: greg-kennedy

topics/game-development/index.md

@@ -1,5 +1,5 @@
 ---
-aliases: game-dev
+aliases: game-dev, gamedev
 display_name: Game Development
 short_description: Game Development is the art of creating games and describes the design, development and release of a game.
 topic: game-development