add nixpkgs/config.nix

.config/nixpkgs/config.nix

@@ -0,0 +1,33 @@
+{
+  # https://nixos.org/manual/nixpkgs/stable/#sec-declarative-package-management
+  # https://github.com/g-w1/nix-configs/blob/main/home.nix
+  packageOverrides = pkgs: with pkgs; {
+    myPackages = pkgs.buildEnv {
+      name = "my-packages";
+      paths = [
+        aerc
+        b3sum
+        cpplint
+
+        cachix
+        hydra-check
+        nixops
+        nix-update
+        nix-diff
+        niff
+        nox
+        nix-du
+        nixfmt
+        statix
+
+        elvish
+        silver-searcher
+        starship
+        ttyper
+
+        nerdfonts
+      ];
+      pathsToLink = [ "/share" "/bin" "/etc" ];
+    };
+  };
+}