feat: add steam_disk_space egg feature to SteamCMD eggs

A new egg feature modal was introduced in Panel v1.7.0 triggering when server has run out of disk space to provide more user-friendly instructions to both admins and normal users. This is unique to SteamCMD specific errors.

game_eggs/steamcmd_servers/pixark/egg-pix-a-r-k.json

@@ -8,7 +8,9 @@
     "name": "PixARK",
     "author": "hello@venatus.digital",
     "description": "A simple Docker container with Wine to run PixARK using Pterodactyl Panel",
-    "features": null,
+    "features": [
+        "steam_disk_space"
+    ],
     "images": [
         "quay.io\/parkervcp\/pterodactyl-images:ubuntu_wine-source"
     ],
@@ -109,4 +111,4 @@
             "rules": "required|string|max:30"
         }
     ]
-}
+}