[SUGGESTION] Add support for custom Data pack items

Hello,

I have a Minecraft Java Edition server on the current version 1.20.1 with some data packs installed on the world. These packs are adding new features with blocks or items to the game (for example [this](https://www.planetminecraft.com/data-pack/mc-paint-create-your-own-custom-paintings/) data pack). I want to have it so that Java Edition players can get these special data pack items from new inventory tabs and not only with commands. Unfortunately, I don't know if this feature is currently supported in the mod, so I wanted to ask you: Can you please add support for data pack items?

Greetings,
Atten :)

The issue names no files, tests, or entry points. First investigate how the mod discovers and populates creative tabs, and whether Minecraft 1.20.1 exposes data-pack-defined items to that system. Done would require a defined approach for making those items available in new inventory tabs, plus tests or a documented manual check.

Written by the indexing model from the issue text.