Docs: Consistently include an empty line between @since tag and @see, @link, or @global, per the documentation standards.

See #49572.

git-svn-id: https://develop.svn.wordpress.org/trunk@48067 602fd350-edb4-49c9-b593-d223f7449a82

src/wp-includes/default-constants.php

@@ -401,6 +401,7 @@ function wp_templating_constants() {
 	 * It will be used as the fallback if the current theme doesn't exist.
 	 *
 	 * @since 3.0.0
+	 *
 	 * @see WP_Theme::get_core_default_theme()
 	 */
 	if ( ! defined( 'WP_DEFAULT_THEME' ) ) {