Restructure to focus on nix.

lib/packages.nix

@@ -0,0 +1,28 @@
+pkgs: let
+  getPackages = dir: let
+    entries = builtins.readDir dir;
+
+    procEntry = name: type: let
+      path = dir + "/${name}";
+    in
+      if type == "directory"
+      then
+        (
+          if builtins.pathExists (path + "/default.nix")
+          then [path]
+          else []
+        )
+      else [];
+  in
+    builtins.concatLists (
+      builtins.attrValues (
+        builtins.mapAttrs procEntry entries
+      )
+    );
+
+  buildPackage = path: {
+    name = builtins.baseNameOf (toString path);
+    value = pkgs.callPackage (path + "/default.nix") {};
+  };
+in
+  builtins.listToAttrs (builtins.map buildPackage (getPackages ../packages))