Benedikt Hiemer

This PR adds `setting.black.flags` making the `black` hook more configurable. Default is no flags. All options are listed [here](https://black.readthedocs.io/en/stable/usage_and_configuration/the_basics.html#command-line-options), it is documented in the nix option. I first thought about...

Lately, I was asking myself if [OpenCloud](https://opencloud.eu/en) could be run on uberspace. That would be amazing. I was trying to run the software on my uberspace. It worked but I...