added Shelf (#509)

Resources/Textures/Structures/Storage/Shelfs/metal.rsi/meta.json

@@ -0,0 +1,29 @@
+{
+  "version": 1,
+  "license": "CC-BY-SA-3.0",
+  "copyright": "Made by Kezu",
+  "size": {
+    "x": 32,
+    "y": 32
+  },
+  "states": [
+    {
+      "name": "base"
+    },
+    {
+      "name": "rbase"
+    },
+    {
+      "name": "locked"
+    },
+    {
+      "name": "unlocked"
+    },
+    {
+      "name": "closed"
+    },
+    {
+      "name": "open"
+    }
+  ]
+}