I18n: Begin introducing translator comments for strings which include placeholders but no accompanying translator comment.

Adds context to one string used in two different contexts for the new user and new site signup email notification.

More to come.

See #38882


git-svn-id: https://develop.svn.wordpress.org/trunk@39323 602fd350-edb4-49c9-b593-d223f7449a82

src/wp-admin/includes/update.php

@@ -200,6 +200,7 @@ function core_update_footer( $msg = '' ) {
 
 	switch ( $cur->response ) {
 	case 'development' :
+		/* translators: 1: WordPress version number, 2: WordPress updates admin screen URL */
 		return sprintf( __( 'You are using a development version (%1$s). Cool! Please <a href="%2$s">stay updated</a>.' ), get_bloginfo( 'version', 'display' ), network_admin_url( 'update-core.php' ) );
 
 	case 'upgrade' :