make snow tiles sound better (#10125)

Resources/Audio/Effects/Footsteps/sources.txt

@@ -6,4 +6,6 @@ https://github.com/vgstation-coders/vgstation13/tree/fbe7abec4cbadf2ad0136983882
 catwalk, floor, plating, tile, hull and wood sfx modified by mirrorcult.
 
 grass1.ogg and grass2.ogg are taken from https://freesound.org/people/D001447733/sounds/464609/ by D001447733 licensed under CC BY-3.0 and split by mirrorcult
-grass3.ogg and grass4.ogg are taken from https://freesound.org/people/jevans27/sounds/563529/ by jevans27 licensed under CC-0 and split/modified by mirrorcult
+grass3.ogg and grass4.ogg are taken from https://freesound.org/people/jevans27/sounds/563529/ by jevans27 licensed under CC-0 and split/modified by mirrorcult
+
+snowstep1.ogg, snowstep2.ogg, snowstep3.ogg, and snowstep4.ogg are taken from https://freesound.org/people/alexo400/sounds/543385/ by alexo400 licensed under CC-0 and split by EmoGarbage404

Resources/Prototypes/SoundCollections/footsteps.yml

@@ -89,7 +89,10 @@
 - type: soundCollection
   id: footstep_snow
   files:
-  - /Audio/Effects/Footsteps/snowstep.ogg
+  - /Audio/Effects/Footsteps/snowstep1.ogg
+  - /Audio/Effects/Footsteps/snowstep2.ogg
+  - /Audio/Effects/Footsteps/snowstep3.ogg
+  - /Audio/Effects/Footsteps/snowstep4.ogg
 
 - type: soundCollection
   id: footstep_grass