Hint at the source file on conflict in `flake new`
Hint at the source file on conflict in `flake new`

Add a pointer to the source file (from the template) when `nix flake new` (or `init`) encounters an already existing file

Fix #6542
NixOS/nix,NixOS/nix,NixOS/nix,NixOS/nix,NixOS/nix