Add todo comments

Author: sirreal

tests/phpunit/data/html5lib-tests/README.md

@@ -6,3 +6,7 @@ This test data was taken from:
 https://github.com/html5lib/html5lib-tests
 
 The sha was `a9f44960a9fedf265093d22b2aa3c7ca123727b9`.
+
+## Instructions
+
+@todo add instructions here.

tests/phpunit/tests/html-api/wpHtmlProcessorHtml5lib.php

@@ -1,7 +1,9 @@
 <?php
 
 /**
- * Unit tests covering WP_HTML_Processor functionality.
+ * Unit tests covering HTML API functionality.
+ *
+ * @todo add descriptive paragraph here.
  *
  * @package WordPress
  * @subpackage HTML-API