Global for Pharo Book - Do it and go.

[jecisc]

We can add some documentation about the "Do it and go" option in the playground to inspect some code inside the playground.

[nicolaihess]

Now there are some descriptions for "do it and go". Although I don't like the one in PharoTour:

• ==Do it and go== additionally opens a ''navigable'' inspector on the side of the playground.

All GT-Inspectors are "navigable".