[$] Understanding Nix flakes

Nix flakes are anexperimental feature of the Nix package-managementtool designed to build projects in a more self-contained and reproducibleway. Despite the feature's experimental status, it has become increasinglypopular for open-source projects to publish flake.nix files that offerpredefined development environments and build automation even when thoserepositories may not offer an upstream package or module for the NixOS Linux distribution. AlthoughNix flakes have a complicated history, and the path for stabilization isuncertain, flakes can provide useful capabilities for projects that choose toinclude them.