Add note about tidelift

README.md

@@ -9,6 +9,8 @@ Full documentation is at [pugjs.org](https://pugjs.org/)
  For discussion join the [chat room](https://gitter.im/pugjs/pug).
 
  You can test drive Pug online [here](https://pugjs.org/).
+
+ [https://tidelift.com/subscription/pkg/npm-pug?utm_source=npm-pug&utm_medium=referral&utm_campaign=readme](Professionally supported pug is now available)
 
  [![Build Status](https://img.shields.io/travis/pugjs/pug/master.svg?style=flat)](https://travis-ci.org/pugjs/pug)
  [![Coverage Status](https://img.shields.io/coveralls/pugjs/pug/master.svg?style=flat)](https://coveralls.io/r/pugjs/pug?branch=master)