Require relations to be defined in the namespace config

[zepatrik]

Is your feature request related to a problem? Please describe.

Currently the namespace config is useless. Later on we will define relations and their effect there: #303

Describe the solution you'd like

For starters we should require relations to be defined in the namespace config. This will allow a seamless migration later on and prevents typos and other small errors.

This feature does not impact the current functionality.

[xbitres]

Isn't this needed in order to have inheritance between relations (example: owner is equivalent of read and write relations) or do you see it implemented in another way?

[zepatrik]

It is not strictly needed. See #877 for how we implemented that. This issue was rather about validation pre rewrites, so we can actually close this.

[xbitres]

Thank you for your answer. It would be cool that the documentation is updated with an example on how to use it, as it was tricky for me to find the issue

[zepatrik]

Yes, we will very soon update a lot of docs around namespace config, e.g. ory/docs#948
Do you have any specific suggestions? What page were you struggling with?