Enable GitHub Discussions

[EwoutH]

I would propose to enable GitHub Discussions. It's an accessible way to interact with this project. Discussions can be a lot more informal than opening an Issue, and is an ideal place for questions and ideas to start.

During a course (at the TU Delft) we could potentially use it as the main Q&A platform. If this is done during multiple years, it will build of a nice collection of implicit documentation. It will also enable students to get a first glimpse of open-source development using Git.

How to enable GitHub Discussions is documented here.

[EwoutH]

@quaquel Was no time in the meeting, could you take a look at this?