JavaScript - ToDoList Retorne fecha y prioridad

const form = document.forms[0]

const taskInput = form.task //para sacar texto de la tarea

const addButton = document.querySelector("#add") //añadir

const cleanButton = document.querySelector("#clean") //limpiar

const emptyButton = document.querySelector("#empty") //borrar

const taskUl = document.querySelector("ul") //donde añadir las tareas en el DOM

let taskArr = []

const savedTasks = localStorage.getItem("tasks")

if(savedTasks){

  taskArr = JSON.parse(savedTasks)

}

function updateList(){

  taskUl.innerHTML = ""

  saveTasks()

  let htmlString = ""

  for( let i = 0; i < taskArr.length; i++){

    const {text, done} = taskArr[i]

    const liString = `<li ${done? 'class="done"' : ""}>

        <input type="checkbox" data-index="${i}" ${done? "checked" : ""}>

        <p>${text}</p>

      </li>`

     htmlString += liString

  }

  taskUl.innerHTML = htmlString

}

updateList()

function saveTasks(){

  const tasksJSON = JSON.stringify(taskArr)

  localStorage.setItem("tasks", tasksJSON)

}

function addTask(){

  const text = taskInput.value

  if(text.length >= 3){

    taskArr.unshift({

      text,

      done: false

    })

    taskInput.value = ""

    updateList()

  } else{

    alert("El texto tiene que tener al menos tres caracteres")

  }

}

function toggleTaskDone(e){

  if(e.target.matches("input")){

    const checkbox = e.target

    const {index} = checkbox.dataset

    const task = taskArr[index]

    task.done = !task.done

    updateList()

  }

}

function clean(){

  const filteredArr = taskArr.filter(task => !task.done)

  taskArr = filteredArr

  updateList()

}

function empty(){

const code = prompt("Para borrar escribe 'BORRAR':")

  if(code === "BORRAR"){

  taskArr = []

  updateList()

  }

}

addButton.addEventListener("click", addTask)

cleanButton.addEventListener("click", clean)

emptyButton.addEventListener("click", empty)

taskUl.addEventListener("click", toggleTaskDone)