Function append

packages/react-stately/src/data/useListData.ts:280–282

(...values: T[])

      dispatch(state => insert(state, 0, ...values));
    },
    append(...values: T[]) {
      dispatch(state => insert(state, state.items.length, ...values));
    },
    remove(...keys: Key[]) {
      dispatch(state => {
        let keySet = new Set(keys);