Mention Windows support explicitly

Author: gaearon

README.md

@@ -5,6 +5,9 @@ Create React apps with no build configuration.
 * [Getting Started](#getting-started) – How to create a new app.
 * [User Guide](https://github.com/facebookincubator/create-react-app/blob/master/packages/react-scripts/template/README.md) – How to develop apps bootstrapped with Create React App.
 
+Create React App works on MacOS, Linux, and Windows.  
+If something doesn’t work please [file an issue](https://github.com/facebookincubator/create-react-app/issues/new).
+
 ## tl;dr
 
 ```sh