Docs: Updates and corrections to various inline docs added in 6.1.

See #55646


git-svn-id: https://develop.svn.wordpress.org/trunk@54284 602fd350-edb4-49c9-b593-d223f7449a82

src/wp-includes/blocks/comments.php

@@ -213,6 +213,7 @@ function register_legacy_post_comments_block() {
 	 * like `_wp_multiple_block_styles`, which is required in this case because
 	 * the block has multiple styles.
 	 */
+	/** This filter is documented in wp-includes/blocks.php */
 	$metadata = apply_filters( 'block_type_metadata', $metadata );
 
 	register_block_type( 'core/post-comments', $metadata );