I18N: Capitalize translator comments consistently, add trailing punctuation.

Includes minor code layout fixes.

See #44360.
Built from https://develop.svn.wordpress.org/trunk@45932


git-svn-id: http://core.svn.wordpress.org/trunk@45743 1a063a9b-81f0-0310-95a4-ce76da25c4cd

wp-includes/class-wp-customize-panel.php

@@ -358,7 +358,7 @@ class WP_Customize_Panel {
 			<div class="accordion-section-title">
 				<span class="preview-notice">
 				<?php
-					/* translators: %s: the site/panel title in the Customizer */
+					/* translators: %s: The site/panel title in the Customizer. */
 					echo sprintf( __( 'You are customizing %s' ), '<strong class="panel-title">{{ data.title }}</strong>' );
 				?>
 				</span>