This shell adds a version of the ~nix~ command that is pre-configured to support Flakes. Flakes are the unit for packaging Nix code in a reproducible and discoverable way. They can have dependencies on other flakes, making it possible to have multi-repository Nix projects. A flake is a filesystem tree that contains a file named =flake.nix=. It specifies some metadata about the flake such as dependencies (inputs), as well as the values such as packages or modules (outputs).
