add all licenses and navi package

pkgs/navi/default.nix

@@ -0,0 +1,23 @@
+{ stdenv, fetchFromGitHub, ... }:
+
+stdenv.mkDerivation rec {
+  version = "2.0.8";
+  name = "navi-${version}";
+
+  src = fetchFromGitHub {
+    owner = "denisidoro";
+    repo = "navi";
+    rev = "v${version}";
+    sha256 = "1kh4s7s595l95xirdb0fvgkdbig3zcfkdiqk8zdz9cfglzcm5192";
+  };
+
+  buildInputs = [ ];
+
+  meta = with stdenv.lib; {
+    description = "An interactive cheatsheet tool for the command-line";
+    homepage = "https://github.com/denisidoro/navi";
+    license = licenses.asl20;
+    platforms = platforms.linux;
+    maintainers = with maintainers; [ mrVanDalo ];
+  };
+}

system/desktop/packages.nix

@@ -12,6 +12,13 @@ let
   #  seafile-shared = unstablePkgs.seafile-shared;
   #};
 
+  allLicenses = let
+    licenses = builtins.map
+      (license: "echo '${license.shortName} : ${license.fullName}'")
+      (builtins.attrValues pkgs.stdenv.lib.licenses);
+  in pkgs.writers.writeBashBin "all-licenses"
+  (lib.concatStringsSep "\n" licenses);
+
   seafileClient =
     pkgs.seafile-client.override { seafile-shared = pkgs.seafile-shared; };
 
@@ -309,6 +316,8 @@ in {
         "$@"
       '')
 
+      allLicenses
+
       memo
       nixfmt
       dateutils