Release X.Y (202?-??-??)

Binary cache stores now have a setting compression-level.
nix develop now has a flag --unpack to run unpackPhase.
Lists can now be compared lexicographically using the < operator.
New built-in function: builtins.groupBy, with the same functionality as Nixpkgs' lib.groupBy, but faster.
Nix now searches for a flake.nix up until git or filesystem boundary.
The TOML parser used by builtins.fromTOML has been replaced by a more compliant one.