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/theme.php

@@ -1234,7 +1234,7 @@ function get_header_image_tag( $attr = array() ) {
 		}
 	}
 
-	/*
+	/**
 	 * Filters the list of header image attributes.
 	 *
 	 * @since 5.9.0