Docs: Fix some docblock syntax errors and add a missing canonical reference.

See #53399, #52867, #38942, #53668


git-svn-id: https://develop.svn.wordpress.org/trunk@52034 602fd350-edb4-49c9-b593-d223f7449a82

src/wp-includes/functions.php

@@ -2635,6 +2635,7 @@ function wp_unique_filename( $dir, $filename, $unique_filename_callback = null )
 		// Check if an image will be converted after uploading or some existing images sub-sizes file names may conflict
 		// when regenerated. If yes, ensure the new file name will be unique and will produce unique sub-sizes.
 		if ( $is_image ) {
+			/** This filter is documented in wp-includes/class-wp-image-editor.php */
 			$output_formats = apply_filters( 'image_editor_output_format', array(), $_dir . $filename, $mime_type );
 			$alt_types      = array();