Add Space Shooter Game section to README

Author: rishiskhare

README.md

@@ -4,3 +4,7 @@
 - Main link: www.rishiskhare.com
 - GitHub pages: www.rishiskhare.github.io
 - Also works: www.rishikhare.me
+
+## Space Shooter Game
+
+![My GitHub Game](game.gif)