Update creating_a_gamebook.md
Update creating_a_gamebook.md

Download and rename Webplayblankgamebook.png, then drop it in the docs/images directory.

It won't let me upload the image.

[![webplayblankgamebook](https://user-images.githubusercontent.com/30656341/40602784-7775f25a-621f-11e8-8efe-c683cd580294.png)](https://user-images.githubusercontent.com/30656341/40602784-7775f25a-621f-11e8-8efe-c683cd580294.png)
textadventures/quest,textadventures/quest,textadventures/quest,textadventures/quest