docs(dialog): update demo wording

Co-authored-by: Benny Powers - עם ישראל חי! <[email protected]>

elements/rh-dialog/demo/no-headings.html

@@ -1,6 +1,6 @@
 <rh-button id="no-headings-trigger">Open</rh-button>
 <rh-dialog accessible-label="This dialog's accessible name" trigger="no-headings-trigger">
-  <p>This dialog uses the <code>accessible-label</code> attribute to define its <code>aria-label</code>.
+  <p>This dialog uses the <code>accessible-label</code> attribute to define its accessible name for assistive technology.
      If the dialog includes a heading, the heading automatically becomes its accessible name—as long as the
      <code>accessible-label</code> attribute does not exist. If neither a heading nor the <code>accessible-label</code>
      attribute are provided, the dialog's accessible name defaults to the text content of its trigger element.