add nix-community cache

base.nix

@@ -1,7 +1,7 @@
 { config, pkgs, lib, inputs, ... }:
 {
   imports = [
-    ./cachix.nix
+    ./cachix.nix # update with `cachix use --mode nixos -d . FOOBAR`
     ./profiles/locale-no.nix
     # results of 'nixos-generate-config'
     # nice to have if i just dump this flake into /etc/nixos on a clean install

cachix/nix-community.nix

@@ -0,0 +1,13 @@
+
+{
+  nix = {
+    settings = {
+      substituters = [
+        "https://nix-community.cachix.org"
+      ];
+      trusted-public-keys = [
+        "nix-community.cachix.org-1:mB9FSh9qf2dCimDSUo8Zy7bkq5CX+/rkCWyvRCYg3Fs="
+      ];
+    };
+  };
+}