Add and display new tags to highlight the ever-growing number of responsive themes available. Fixes #21442.

Props Otto42 and lancewillett.

Built from https://develop.svn.wordpress.org/trunk@26711


git-svn-id: http://core.svn.wordpress.org/trunk@26600 1a063a9b-81f0-0310-95a4-ce76da25c4cd

wp-admin/includes/theme.php

@@ -197,9 +197,10 @@ function get_theme_feature_list( $api = true ) {
 			'right-sidebar' => __( 'Right Sidebar' ),
 		),
 
-		__( 'Width' ) => array(
-			'fixed-width'    => __( 'Fixed Width' ),
-			'flexible-width' => __( 'Flexible Width' ),
+		__( 'Layout' ) => array(
+			'fixed-layout'      => __( 'Fixed Layout' ),
+			'fluid-layout'      => __( 'Fluid Layout' ),
+			'responsive-layout' => __( 'Responsive Layout' ),
 		),
 
 		__( 'Features' ) => array(