Bundled Themes: Declare support for the `html5` feature `navigation-widgets`.

Widgets that output a list of links are now wrapped within `<nav>` elements to improve semantics and accessibility.

The `<nav>` elements are native landmark regions, which helps assistive technology users to navigate through them.

Follow-up to [48349], [49177].

Props hareesh-pillai, justinahinon, afercia, williampatton.
Fixes #51445.

git-svn-id: https://develop.svn.wordpress.org/trunk@49208 602fd350-edb4-49c9-b593-d223f7449a82

src/wp-content/themes/twentyfifteen/functions.php

@@ -102,6 +102,7 @@ if ( ! function_exists( 'twentyfifteen_setup' ) ) :
 				'caption',
 				'script',
 				'style',
+				'navigation-widgets',
 			)
 		);
 

src/wp-content/themes/twentyfourteen/functions.php

@@ -146,6 +146,7 @@ if ( ! function_exists( 'twentyfourteen_setup' ) ) :
 				'caption',
 				'script',
 				'style',
+				'navigation-widgets',
 			)
 		);
 

src/wp-content/themes/twentynineteen/functions.php

@@ -76,6 +76,7 @@ if ( ! function_exists( 'twentynineteen_setup' ) ) :
 				'caption',
 				'script',
 				'style',
+				'navigation-widgets',
 			)
 		);
 

src/wp-content/themes/twentyseventeen/functions.php

@@ -79,6 +79,7 @@ function twentyseventeen_setup() {
 			'caption',
 			'script',
 			'style',
+			'navigation-widgets',
 		)
 	);
 

src/wp-content/themes/twentysixteen/functions.php

@@ -108,6 +108,7 @@ if ( ! function_exists( 'twentysixteen_setup' ) ) :
 				'caption',
 				'script',
 				'style',
+				'navigation-widgets',
 			)
 		);
 

src/wp-content/themes/twentythirteen/functions.php

@@ -168,6 +168,7 @@ function twentythirteen_setup() {
 			'caption',
 			'script',
 			'style',
+			'navigation-widgets',
 		)
 	);
 

src/wp-content/themes/twentytwenty/functions.php

@@ -105,6 +105,7 @@ function twentytwenty_theme_support() {
 			'caption',
 			'script',
 			'style',
+			'navigation-widgets',
 		)
 	);