update, added assets

assets/wallpapers/default.nix

@@ -0,0 +1,21 @@
+{ stdenv, lib, ... }:
+let
+  inherit (lib.fileset) toSource unions intersection maybeMissing gitTracked;
+  sourceFiles = unions [
+    (gitTracked ./.)
+    (maybeMissing ./cap_blow.png)
+    (maybeMissing ./cap_filter.png)
+  ];
+in
+lib.fileset.trace sourceFiles
+stdenv.mkDerivation {
+  name = "my-wallpapers";
+  src = toSource {
+    root = ./.;
+    fileset = sourceFiles;
+  };
+  installPhase = ''
+    mkdir -p $out/usr/local/share/wallpapers
+    cp -r *.{jpg,jpeg,png} $out/usr/local/share/wallpapers/
+  '';
+}