refactor: update entity import

Author: jorenrui

lib/entity.js

@@ -4,7 +4,7 @@ import { Events } from './entity/events'
 import { Attributes } from './entity/attributes'
 import { State } from './state'
 
-export default class Entity {
+export class Entity {
   constructor(el) {
     this.element = el
     this.tagName = el.tagName

lib/main.js

@@ -1,4 +1,4 @@
-import Entity from './entity'
+import { Entity } from './entity'
 import { Lexer } from './generators/lexer'
 import { observeDOM } from './generators/observer'
 import { State } from './state'