Update the documentation properly once the versioning is in place.

[ccarouge]

Updates needed:

• [x] use list of dict for realisation
• [x] add build_script option
• [x] change User guide to use sub-commands and not command line options
• [ ] add information on expected output when running benchcab

@SeanBryan51 anything else?

[SeanBryan51]

That sounds about right. Should we add stuff from more recent work such as #69 and #76?

[ccarouge]

I'm happy to add stuff about #69 on the output messages because it should get into the code base soon, likely before the PR for this issue. But for #76, I'd prefer the update to the documentation to be a part of the same PR as the work on the code itself, since it will come in later.