Stories: CSE Machine not available in the UI

[martin-henz]

The stories workspaces for Chapter 3 and 4 should show the CSE Machine.

[RichDom2185]

Last time I recalled, CSE Machine gets confused due to the different code blocks sharing the same environment, hence I commented away the tab. Will look into this again.

[martin-henz]

Yes, would be great. Then I can make a story to introduce the tool. We have a story for each of our tools, so far.