add note about label attribute

Author: josepharhar

source

@@ -56719,6 +56719,11 @@ interface <dfn interface>HTMLSelectedContentElement</dfn> : <span>HTMLElement</s
   can be used to declaratively show the selected <code>option</code> element's contents within the
   <code>select</code> element's first child <code>button</code> element.</p>
 
+  <p class="note">The <code>option</code> element's <code data-x="attr-option-label">label</code>
+  attribute can be used to render a visible label for the option, but the
+  <code>selectedcontent</code> element will not reflect the content of the <code
+  data-x="attr-option-label">label</code> attribute.</p>
+
   <p w-dev>Every time the selected <code>option</code> of a <code>select</code> switches from one
   option to another, the <code>selectedcontent</code> element removes all of its children and
   replaces them with a new copy of the DOM structure of the <code>select</code>'s selected