rputils

Adds custom item properties, for now it is only submerged predicate that lets items change when the player is underwater. More properties coming soon. 

example with [Weskerson's torches](https://modrinth.com/resourcepack/weskersons-torches)



on modrinth:https://modrinth.com/mod/rpputils

how to use 
on 
```
minecraft/items
```

```
{
  "model": {
    "type": "minecraft:condition",
    "property": "rj:submerged",
    "on_true": {
      "type": "minecraft:model",
      "model": "minecraft:item/underwater_item"
    },
    "on_false": {
      "type": "minecraft:model",
      "model": "minecraft:item/normal_item"
    }
  }
}

```