Add aseprite flipbook schema (#197)

* Add aseprite flipbook schema

* Probably hash is unneeded

* Add new UI texture definition file to compress_specification.json

vscode-settings.json

@@ -368,7 +368,7 @@
         "*RP*/textures/*/**/*.{json,jsonc,json5}",
         "*rp*/textures/*/**/*.{json,jsonc,json5}"
       ],
-      "url": "https://raw.githubusercontent.com/Blockception/Minecraft-bedrock-json-schemas/main/resource/textures/nine_slice.json"
+      "url": "https://raw.githubusercontent.com/Blockception/Minecraft-bedrock-json-schemas/main/resource/textures/ui_texture_definition.json"
     }
   ]
 }