update: mention tour is in-browser on get-started

Author: orblivion

docs/topics/getting-started.md

@@ -3,7 +3,8 @@
 Kotlin is a modern but already mature programming language designed to make developers happier.
 It's concise, safe, interoperable with Java and other languages, and provides many ways to reuse code between multiple platforms for productive programming.
 
-To start, why not take our tour of Kotlin? This tour covers the fundamentals of the Kotlin programming language.
+To start, why not take our tour of Kotlin? This tour covers the fundamentals of the Kotlin programming language and can
+be completed entirely within your browser.
 
 <a href="kotlin-tour-welcome.md"><img src="start-kotlin-tour.svg" width="700" alt="Start the Kotlin tour"/></a>