added some first contributing guidelines and changed the config skeleton

README.md

@@ -287,12 +287,12 @@ something like this:
 Like with all FS projects, you are welcome to contribute. Work is done usually by the person that is most annoyed
 by the circumstances or by the person that didn't run fast enough. So we are happy if we get help. That doesn't
 mean that we don't need to have some level of quality, people after us needs to work with it. It is live infrastructure
-and downtime hurts someone (and in the wrong moment even really bad (Matheball ticket sales for example).
+and downtime hurts someone (and in the wrong moment even really bad (Matheball ticket sales for example)).
 
 So here are some Guidelines.
 
 ## Coding style and linting.
-If you run `nix check` there are automated checks in place, please make sure to pass them.
+If you run `nix flake check` there are automated checks in place, please make sure to pass them.
 There is also a code autoformatter (`alejandra`) incorporated into those. You can also install
 them into your local git repository as pre-commit hooks, and setting up a shell that has
 even more tooling by running `nix develop`. That will give you a bash in which you can run