docs(toast): add version to layout (#2800)

Author: liamdebeasi

static/usage/v6/toast/layout/index.md

@@ -8,6 +8,7 @@ import angular_example_component_html from './angular/example_component_html.md'
 import angular_example_component_ts from './angular/example_component_ts.md';
 
 <Playground
+  version="6"
   devicePreview
   code={{
     javascript,