update showcase tree structure

[agitana]

No description provided.

[MauricioUyaguari]

I don't think we need subfolders under Build a data model.
I think for this we should have one or 2 showcases with a detailed usage of Class, Associations, Enum and a Diagram.
If we need to do a further split down we could in the future but I think for now thats fine.

[MauricioUyaguari]

Lets remove the serializable folder please.

[MauricioUyaguari]

text elements don't really interact with the model. we can just rename that folder to
Use text element

[MauricioUyaguari]

For now external format is fine, we should do another walkthrough. As
Basically we should probably have it something like

• External Format
  • Types
  • Writing Internalize Func (Reading External Format)
  • Writing Externalize Func (Writing to External Format)

[agitana]

thanks @MauricioUyaguari actioned your feedback can you please review?