Adds two new cave floors (#9873)

Resources/Prototypes/Tiles/floors.yml

@@ -811,3 +811,35 @@
   thermalConductivity: 0.04
   heatCapacity: 10000
 
+# Caves
+- type: tile
+  id: FloorCave
+  name: cave
+  texture: cave
+  variants: 7
+  placementVariants: [0, 1, 2, 3, 4, 5, 6]
+  base_turfs:
+  - space
+  is_subfloor: false
+  can_crowbar: false
+  footstep_sounds:
+    collection: footstep_asteroid
+  friction: 0.30
+  thermalConductivity: 0.04
+  heatCapacity: 10000
+  
+- type: tile
+  id: FloorCaveDrought
+  name: cave drought
+  texture: cavedrought
+  variants: 8
+  placementVariants: [0, 1, 2, 3, 4, 5, 6, 7]
+  base_turfs:
+  - space
+  is_subfloor: false
+  can_crowbar: false
+  footstep_sounds:
+    collection: footstep_asteroid
+  friction: 0.30
+  thermalConductivity: 0.04
+  heatCapacity: 10000

Resources/Textures/Tiles/attributions.yml

@@ -34,3 +34,8 @@
   license: "CC-BY-NC-SA-3.0"
   copyright: "by WALPVRGIS for Goonstation, taken at commit 236551b95a5b24917c72f3069223026b2dc4e690 from floors.dmi"
   source: "https://github.com/goonstation/goonstation"
+  
+- files: ["cave.png", "cavedrought.png"]
+  license: "CC-BY-NC-SA-3.0"
+  copyright: "Mojave-Sun, taken at commit 0587dd16e28108bdf0b0a28e2caae4319845e861"
+  source: "https://github.com/Mojave-Sun/mojave-sun-13"