Move wiki to regular repo

[heidivanparys]

I think we should consider having the current wiki pages moved to the main repo. That way, it will be much easier for others using the regular workflow of forking and creating pull requests.

[jetgeo]

Agree in principle. But perhaps also move into the HMMG repo. Unfortunately, I am struggling to find time to work on this matter. Any help is welcome!

[heidivanparys]

But perhaps also move into the HMMG repo.

I intended to have a direct link to https://github.com/ISO-TC211/UML-Best-Practices in ISO 19103, we should reach a decision before the standard is published.