feat(core): add play button component (#383)

packages/html/src/define/ui/play-button.ts

@@ -1 +1,9 @@
-// TODO: Implement PlayButtonElement then register it here
+import { PlayButtonElement } from '../../ui/play-button/play-button-element';
+
+customElements.define(PlayButtonElement.tagName, PlayButtonElement);
+
+declare global {
+  interface HTMLElementTagNameMap {
+    [PlayButtonElement.tagName]: PlayButtonElement;
+  }
+}