Add auto-update support

[AdamCalculator]

hello, I am the developer of the DynamicPack mod which allows resource packs to update automatically if their owner configures one single file

This is what it should look like.
name: dynamicmcpack.json

{
    "formatVersion": 1,
    "current": {
      "version_number": "1"
    },
    "remote": {
      "game_version": "1.20.3",
      "modrinth_project_id": "faithful-64x",
      "type": "modrinth"
    }
}