Twenty Twelve: Document the twentytwelve_credits action hook.

Follow-up to [21261], [60738].

Props pmbaldha, sabernhardt.
See #63648.

git-svn-id: https://develop.svn.wordpress.org/trunk@60739 602fd350-edb4-49c9-b593-d223f7449a82

Author: SergeyBiryukov

src/wp-content/themes/twentytwelve/footer.php

@@ -12,7 +12,14 @@
 	</div><!-- #main .wrapper -->
 	<footer id="colophon" role="contentinfo">
 		<div class="site-info">
-			<?php do_action( 'twentytwelve_credits' ); ?>
+			<?php
+			/**
+			 * Fires before the Twenty Twelve footer text for footer customization.
+			 *
+			 * @since Twenty Twelve 1.0
+			 */
+			do_action( 'twentytwelve_credits' );
+			?>
 			<?php
 			if ( function_exists( 'the_privacy_policy_link' ) ) {
 				the_privacy_policy_link( '', '<span role="separator" aria-hidden="true"></span>' );