docs/Update readme getting started link (#47)

#### Description
Update link in readme to go to getting started instead of welcome.

Author: mattyoung-improbable

README.md

@@ -4,6 +4,6 @@ This starter project is designed to help you get started quickly with the [Spati
 
 ## Getting started
 
-For information on installing, running and playing the FPS Starter Project, please see our [welcome page](https://docs.improbable.io/unity/alpha/welcome).
+For information on installing, running and playing the FPS Starter Project, please see our [getting started guide](https://docs.improbable.io/unity/alpha/content/get-started/get-started).
 
 © 2018 Improbable