Added an introductory role playing activity into resources.
This aims to familiarise children with the way we use code to "talk to computers".
It also introduces the practices of testing and debugging code, collaboratively.
Renamed Introduction.md as README.md
Changed the formatting for texts intended as "script for the volunteer to say", from code blocks (more appropriate) blockquotes.
Small tweaks, added "end result" example picture.
Updated instructions image.
Merge pull request #103 from matteomenapace/master

New role playing activity