Add cachix repo

Author: cadkin

flake.nix

@@ -98,5 +98,10 @@
         );
       };
     };
+
+    nixConfig = {
+        extra-substituters = [ "https://mdfbaam.cachix.org" ];
+        extra-trusted-public-keys = [ "mdfbaam.cachix.org-1:WCQinXaMJP7Ny4sMlKdisNUyhcO2MHnPoobUef5aTmQ=" ];
+    };
   });
 }