npm install @gridsheet/preact-core @gridsheet/functionsimport { GridSheet } from "@gridsheet/preact-core";import { useSpellbook } from "@gridsheet/preact-core/spellbook"; export function SheetDemo() { const book = useSpellbook(); return ( <GridSheet book={book} sheetName="Sheet1" initialCells={{ A1: { value: "Hello" }, B2: { value: "=SUM(A2:B2)" }, }} /> );}