refactor: nix-path/ -> nix/

hosts/common/default.nix

@@ -9,7 +9,7 @@
     ./ids.nix
     ./machine-id.nix
     ./net
-    ./nix-path
+    ./nix
     ./persist.nix
     ./polyunfill.nix
     ./programs

hosts/common/nix/default.nix

@@ -8,7 +8,7 @@
     # "nixpkgs-overlays=${../../..}/hosts/common/nix-path/overlay"
     # as long as my system itself doesn't rely on NIXPKGS at runtime, we can point the overlays to git
     # to avoid switching so much during development
-    "nixpkgs-overlays=/home/colin/dev/nixos/hosts/common/nix-path/overlay"
+    "nixpkgs-overlays=/home/colin/dev/nixos/hosts/common/nix/overlay"
   ];
 
   # ensure new deployments have a source of this repo with which they can bootstrap.