Merge pull request #94 from ruan-brandao/update-overview-scene-guide

Correct typo on overview_scene guide

Thank you very much!

Author: boydm

guides/overview_scene.md

@@ -88,7 +88,7 @@ you are ready.
       push_graph( @graph )
 
       state = %{
-        graph: @graph
+        graph: @graph,
         viewport: opts[:viewport]
       }