Docker guide in English

[BoerBas]

Docker guide in develop in English

[joeribekker]

I added Docker documentation (PR) in English for the ZTC. The Docker container is slightly different (I choose lightweight container over Haarlem-like containers).

Might be useful to look at for the ZM: https://github.com/maykinmedia/zaaktypecataloguscomponent/blob/e581ca81f3305abf085b01458e15343fa14898de/INSTALL.rst