Add tidy-html5 website at README

Author: alefteris

README.md

@@ -1,7 +1,7 @@
 SublimeLinter-html-tidy
 =========================
 
-This linter plugin for [SublimeLinter](https://github.com/SublimeLinter/SublimeLinter3) provides an interface to tidy (either the [html4](http://tidy.sourceforge.net) or [html5]() version). It will be used with files that have the “HTML” syntax.
+This linter plugin for [SublimeLinter](https://github.com/SublimeLinter/SublimeLinter3) provides an interface to tidy (either the [html4](http://tidy.sourceforge.net) or [html5](http://w3c.github.io/tidy-html5/) version). It will be used with files that have the “HTML” syntax.
 
 ## Installation
 SublimeLinter 3 must be installed in order to use this plugin. If SublimeLinter 3 is not installed, please follow the instructions [here](https://github.com/SublimeLinter/SublimeLinter.github.io/wiki/Installation).