message: chore(accordion): add shadow parts
diff: @@ -57,6 +57,10 @@ const observeResize = (observer: ResizeObserver, elem: Element) => {
  * The custom event fired before this accordion item is being toggled upon a user gesture.
  * Cancellation of this event stops the user-initiated action of toggling this accordion item.
  * @fires bx-accordion-item-toggled - The custom event fired after this accordion item is toggled upon a user gesture.
  + * @csspart expando The expando button.
  + * @csspart expando-icon The expando icon.
  + * @csspart title The title.
  + * @csspart content The content.
  */
  @customElement(`${prefix}-accordion-item`)
  class BXAccordionItem extends FocusMixin(LitElement) {
  @@ -165,6 +169,7 @@ class BXAccordionItem extends FocusMixin(LitElement) {
  return html`
  <button
  type="button"
  + part="expando"
  class="${prefix}--accordion__heading"
  aria-controls="content"
  aria-expanded="${String(Boolean(open))}"
  @@ -172,11 +177,12 @@ class BXAccordionItem extends FocusMixin(LitElement) {
  @keydown="${handleKeydownExpando}"
  >
  ${ChevronRight16({
  + part: 'expando-icon',
  class: `${prefix}--accordion__arrow`,
  })}
  - <div class="${prefix}--accordion__title"><slot name="title">${titleText}</slot></div>
  + <div part="title" class="${prefix}--accordion__title"><slot name="title">${titleText}</slot></div>
  </button>
  - <div id="content" class="${contentClasses}"><slot></slot></div>
  + <div id="content" part="content" class="${contentClasses}"><slot></slot></div>
  `;
  }
  