[Grok-dev] Improvements to the tutorial

[Philipp von Weitershausen]

An IRC conversation just now made me realize that our tutorial isn't as 
far along as I thought it would be. For instance, it doesn't quite go 
into much detail about containers.

I remember Luciano had enhanced the tutorial with a complete CRUD story, 
covering containers excessively. It'd be supercool if this could finally 
be merged into the tutorial.