Add LaunchScreen@2x and LaunchScreen@3x

Author: marcoroth

RubyEvents/Assets.xcassets/LaunchScreen.imageset/Contents.json

@@ -6,10 +6,12 @@
       "scale" : "1x"
     },
     {
+      "filename" : "[email protected]",
       "idiom" : "universal",
       "scale" : "2x"
     },
     {
+      "filename" : "[email protected]",
       "idiom" : "universal",
       "scale" : "3x"
     }