add a link to roadmap

Author: bobzhang

README.md

@@ -18,6 +18,7 @@ See [CONTRIBUTING.md](CONTRIBUTING.md).
 * Thanks to [ninja-build](https://ninja-build.org), BuckleScript also comes with a blazing fast build tool on top of it, `ninja` is a truly [well engineered](http://aosabook.org/en/posa/ninja.html) scalable build tool
 * Thanks to [Bloomberg](https://www.techatbloomberg.com) and [Facebook](https://github.com/facebook/). This project began at Bloomberg and was published in 2016; without the support of Bloomberg, it would not have happened. This project's funded by Facebook since July/2017
 
+## [Roadmap](https://github.com/bucklescript/bucklescript/wiki)
 
 ## Licensing