Added nixgreety package

pkgs/programs/nixgreety.nix

@@ -0,0 +1,19 @@
+{ pkgs, ... }:
+
+with pkgs;
+rustPlatform.buildRustPackage {
+  pname = "nixgreety";
+  version = "master";
+
+  src = fetchFromGitea {
+    domain = "git.bulthuis.dev";
+    owner = "Jan";
+    repo = "nixgreety";
+    rev = "4b5f812e95f6359ce61aef685005dc4013f0fb5f";
+    hash = "sha256-/eikqX/2byDi04v1XvsBVva1Vs7OGLl/cC/Vrq+QF9A=";
+  };
+
+  cargoHash = "sha256-pklKVzYoChRqPZ/D3BsMGnaBFd615TKbvoAy7iU8UtA=";
+
+  useFetchCargoVendor = true;
+}