flake: add NUR overlay

flake.lock

@@ -16,9 +16,25 @@
         "type": "github"
       }
     },
+    "nur": {
+      "locked": {
+        "lastModified": 1612513831,
+        "narHash": "sha256-Ma1l+wgplQDvcffE9llq2eQr8//xmR650StuciRQVns=",
+        "owner": "nix-community",
+        "repo": "NUR",
+        "rev": "e7ee315a84eef33a6d5975ce50a7697f05ae83fa",
+        "type": "github"
+      },
+      "original": {
+        "owner": "nix-community",
+        "repo": "NUR",
+        "type": "github"
+      }
+    },
     "root": {
       "inputs": {
-        "nixpkgs": "nixpkgs"
+        "nixpkgs": "nixpkgs",
+        "nur": "nur"
       }
     }
   },

flake.nix

@@ -2,9 +2,10 @@
   description = "Nixos configuration with flakes";
   inputs = {
     nixpkgs.url = "github:NixOS/nixpkgs/nixos-unstable";
+    nur.url = "github:nix-community/NUR";
   };
 
-  outputs = { self, nixpkgs }: {
+  outputs = { self, nixpkgs, nur }: {
     nixosConfigurations.porthos = nixpkgs.lib.nixosSystem {
       system = "x86_64-linux";
       modules =
@@ -17,6 +18,7 @@
               then self.rev
               else throw "Refusing to build from a dirty Git tree!";
           })
+          { nixpkgs.overlays = [ nur.overlay ]; }
           ./configuration.nix
         ];
     };