Accessibility: Remove title attributes from the Meta widget.

- removes the `Powered by WordPress, state-of-the-art semantic personal publishing platform.` title attribute
- removes the title attribute from the abbreviations: contrary to a common belief, title attributes on abbreviations are only available to a minority of users, see https://developer.paciellogroup.com/blog/2019/03/short-note-the-abbreviation-appreciation-society/
- changes the term `RSS` to `feed`, as `RSS` is a technical term not all users are supposed to be familiar with
- improves the `widget_meta_poweredby` filter documentation

Props nishitlangaliya, chetan200891, audrasjb.
See #46980, #24766.
Fixes #46978.


git-svn-id: https://develop.svn.wordpress.org/trunk@45728 602fd350-edb4-49c9-b593-d223f7449a82

src/wp-includes/widgets/class-wp-widget-meta.php

@@ -56,24 +56,23 @@ class WP_Widget_Meta extends WP_Widget {
 			<ul>
 			<?php wp_register(); ?>
 			<li><?php wp_loginout(); ?></li>
-			<li><a href="<?php echo esc_url( get_bloginfo( 'rss2_url' ) ); ?>"><?php _e( 'Entries <abbr title="Really Simple Syndication">RSS</abbr>' ); ?></a></li>
+			<li><a href="<?php echo esc_url( get_bloginfo( 'rss2_url' ) ); ?>"><?php _e( 'Entries feed' ); ?></a></li>
-			<li><a href="<?php echo esc_url( get_bloginfo( 'comments_rss2_url' ) ); ?>"><?php _e( 'Comments <abbr title="Really Simple Syndication">RSS</abbr>' ); ?></a></li>
+			<li><a href="<?php echo esc_url( get_bloginfo( 'comments_rss2_url' ) ); ?>"><?php _e( 'Comments feed' ); ?></a></li>
 			<?php
 			/**
-			 * Filters the "Powered by WordPress" text in the Meta widget.
+			 * Filters the "WordPress.org" list item HTML in the Meta widget.
 			 *
 			 * @since 3.6.0
 			 * @since 4.9.0 Added the `$instance` parameter.
 			 *
-			 * @param string $title_text Default title text for the WordPress.org link.
+			 * @param string $html     Default HTML for the WordPress.org list item.
 			 * @param array  $instance Array of settings for the current widget.
 			 */
 			echo apply_filters(
 				'widget_meta_poweredby',
 				sprintf(
-					'<li><a href="%s" title="%s">%s</a></li>',
+					'<li><a href="%1$s">%2$s</a></li>',
 					esc_url( __( 'https://wordpress.org/' ) ),
-					esc_attr__( 'Powered by WordPress, state-of-the-art semantic personal publishing platform.' ),
 					__( 'WordPress.org' )
 				),
 				$instance