feat: add some comment

entry/src/main/ets/common/CommonConstant.ets

+// 样式集合
 export default class CommonConstants {
 
   //每列宽度

entry/src/main/ets/entryability/EntryAbility.ets

+// 好像是启动时加载的类
 import { AbilityConstant, UIAbility, Want } from '@kit.AbilityKit';
 import { hilog } from '@kit.PerformanceAnalysisKit';
 import { window } from '@kit.ArkUI';

entry/src/main/ets/entrybackupability/EntryBackupAbility.ets

+// 好像没用上
 import { hilog } from '@kit.PerformanceAnalysisKit';
 import { BackupExtensionAbility, BundleVersion } from '@kit.CoreFileKit';
 

entry/src/main/ets/pages/Index.ets

+// 首页：导航栏+子页面
 import {LocalPage} from '../pages/LocalPage'
 import {WebPage} from '../pages/WebPage'
 import DataModel from '../viewmodel/DataModel'

entry/src/main/ets/pages/LocalPage.ets

+// Todolist页面
 import ToDoItem from '../view/TodoItem'
 import CommonConstants from '../common/CommonConstant'
 import TodoItemModel from '../viewmodel/TodoItemModel'

entry/src/main/ets/pages/WebPage.ets

+// 原来作业要求的网页版，应该没啥用
 import { webview } from '@kit.ArkWeb'
 import TodoItemModel from '../viewmodel/TodoItemModel'
 import { http } from '@kit.NetworkKit'

entry/src/main/ets/view/AddItem.ets

+// 添加事项页面
 import CommonConstants from '../common/CommonConstant'
 import { http } from '@kit.NetworkKit'
 import { promptAction } from '@kit.ArkUI';

entry/src/main/ets/view/ItemDetail.ets

+// 事项详情页面
 import CommonConstants from '../common/CommonConstant'
 import DataModel from '../viewmodel/DataModel'
 import TodoItemModel from '../viewmodel/TodoItemModel'

entry/src/main/ets/view/TodoItem.ets

+// 单个事项
 import CommonConstants from '../common/CommonConstant'
 import TodoItemModel from '../viewmodel/TodoItemModel'
 import { promptAction } from '@kit.ArkUI'

entry/src/main/ets/viewmodel/DataModel.ets

+// 数据处理
 import TodoItemModel from './TodoItemModel'
 import {preferences} from '@kit.ArkData'
 

entry/src/main/ets/viewmodel/TodoItemModel.ets

+// TodoItem数据类
 export default class TodoItemModel {
   itemName: string