Modals - add size property to sidebar (#444)

* add size property

* add jsdocs

---------

Co-authored-by: Jacob Overgaard <[email protected]>

Author: JesmoDev

packages/uui-modal/lib/uui-modal-sidebar.element.ts

@@ -1,9 +1,17 @@
 import { css, html, PropertyValueMap } from 'lit';
-import { customElement } from 'lit/decorators.js';
+import { customElement, property } from 'lit/decorators.js';
 import { UUIModalElement } from './uui-modal.element';
 
+export type UUIModalSidebarSize = 'small' | 'medium' | 'large' | 'full';
+
 @customElement('uui-modal-sidebar')
 export class UUIModalSidebarElement extends UUIModalElement {
+  /**
+   * @attr
+   */
+  @property({ reflect: true })
+  size: UUIModalSidebarSize = 'full';
+
   constructor() {
     super();
     this.addEventListener('close', this.#onClose.bind(this));