v1.4.0

Changes:

• Updated dev dependencies (nixpkgs/devshell)
• Updated flake-utils dependency
• Added function utils.lib.genPkgOverlay to create an overlay for an input's package @Pacman99
• Export autoGenFromInputs module for nix-darwin
• Improved docs @gcoakes, @montchr, @Sohalt
• Fixed ca-references in extra-experimental-features is causing errors @wahjava
• Added a few improved module assertions to avoid undefined behavior
• Darwin support @Enzime, @bbbbbailey
• Fixed flake-utils-plus evaluation edge case #134 @ravensiris
• Fix nixpkgs compatibility issues caused by NixOS/nixpkgs#257458 @andrevmatos
• Expose fup-repl as a blueprint flake attribute