append api to lib name

src/Umbraco.Web.UI.Client/libs/README.md

@@ -40,7 +40,7 @@ Create an umbraco-package.json file in the root of your package.
 Then create a dashboard.js file the same folder.
 
 ```javascript
-import { UmbElementMixin } from '@umbraco-cms/backoffice/element';
+import { UmbElementMixin } from '@umbraco-cms/backoffice/element-api';
 import { UMB_NOTIFICATION_CONTEXT_TOKEN } from '@umbraco-cms/backoffice/notification';
 
 const template = document.createElement('template');
@@ -106,12 +106,11 @@ Then go to the element located in `src/my-element.ts` and replace it with the fo
 // src/my-element.ts
 import { LitElement, html } from 'lit';
 import { customElement } from 'lit/decorators.js';
-import { UmbElementMixin } from '@umbraco-cms/backoffice/element';
+import { UmbElementMixin } from '@umbraco-cms/backoffice/element-api';
 import { UmbNotificationContext, UMB_NOTIFICATION_CONTEXT_TOKEN } from '@umbraco-cms/backoffice/notification';
 
 @customElement('my-element')
 export default class MyElement extends UmbElementMixin(LitElement) {
-
 	private _notificationContext?: UmbNotificationContext;
 
 	constructor() {