Refactor to a clear folder structure of analysis and design documents

[martinmo]

The current folder structure under src/main/asciidoc doesn't distinguish between analysis and design documents:

src/main/asciidoc
├── diagrams
│   └── images
└── images
    ├── Sequence_Diagrams
    └── gui

This should be reorganized, such that the scope and purpose of the models and the corresponding exported diagrams are clear.

[martinmo]

Btw, in the kickstart project we have a good structure:

src/main/asciidoc
├── evaluations
├── images
├── models
│   ├── analysis
│   └── design
└── protocols

[martinmo]

Note to self: update links on the ST chair's website when done.