[Sound on/off] button returned on cover page of the story (page with lab...

...el ‘Tiny’s world’.

So now [Sound on/off] button, aka Narration button, is shown on first two pages of the story, ‘Tiny’s world’ and ’Tiny loves her tiny bed’.
Drawbacks: found that page where [Sound on/off] button is shown and page where [Go to bookmark] button is shown are set with the same element of <scene> tag in story.xml (title=“true”).
So now both [Sound on/off] button and [Go to bookmark] button are shown on those first two pages of the story. if that is not OK, should be fixed.