Declaring Nested Lists the Block Type for PortableText

 list: {
    // Ex. 1: customizing common list types
    bullet: ({children}) => <ul className="mt-xl">{children}</ul>,
    number: ({children}) => <ol className="mt-lg">{children}</ol>,

    // Ex. 2: rendering custom lists
    checkmarks: ({children}) => <ol className="m-auto text-lg">{children}</ol>,
  },