Slot data documentation

Issue

Documentation is wrong about slot datas (i assume)

Solution

I spent almost an hour to understand that content was in fact just a prismarine item.toNotch.
Would be nice for new users to precise explicitly this matter in docs somehow.

The correct format is the following (or maybe i just don't know how to read the doc table ?)

import prismarineItem from "prismarine-item"
const Item = prismarineItem('1.12.1')

const stick = new Item(280, 5)
const notchStick = Item.toNotch(stick)
this.client.write('window_items', {
    windowId: 0,
    items: [0, 0, 0, notchStick, notchStick, 0, notchStick],
})

Locate the slot data documentation and its table, then compare the description of content with the issue's Item.toNotch(stick) example. Update the documentation to explicitly state the expected content format and ensure the example matches it.