remove sponsorship line

Author: jaimeiniesta

readme.mkd

@@ -121,13 +121,9 @@ guide][official], which forms the basis of much of this document.
 Copyright 2012 Tom Vincent <http://tlvince.com/contact>, licensed under the
 [Creative Commons Attribution 3.0 Unported License][cc].
 
-Need to site-wide validate your site? Like beautiful reports? Try
-[MarkupValidator][]!
-
   [cc]: http://creativecommons.org/licenses/by/3.0/
   [home]: http://jigsaw.w3.org/css-validator/
   [vagrant]: http://vagrantup.com/
   [vagrantdl]: http://downloads.vagrantup.com/tags/v1.0.5
   [official]: http://jigsaw.w3.org/css-validator/DOWNLOAD.html
   [localhost8080]: http://localhost:8080/css-validator
-  [markupvalidator]: http://markupvalidator.com