Initial commit. State 04.2021.

wp-content/themes/twentyfourteen/js/featured-content-admin.js

@@ -0,0 +1,9 @@
+/**
+ * Twenty Fourteen Featured Content admin behavior: add a tag suggestion
+ * when changing the tag.
+ */
+/* global ajaxurl:true */
+
+jQuery( document ).ready( function( $ ) {
+	$( '#customize-control-featured-content-tag-name input' ).suggest( ajaxurl + '?action=ajax-tag-search&tax=post_tag', { delay: 500, minchars: 2 } );
+});