meta: Add go-thumbnailer

It was surprisingly easy to package go-thumbnailer with nix, and it may
be a fun side project to make a pull request for nixpkgs.

applications/thunar/go-thumbnailer/default.nix

@@ -0,0 +1,32 @@
+{ lib
+, stdenv
+, buildGoModule
+, fetchFromGitHub
+}:
+
+buildGoModule rec {
+  pname = "go-thumbnailer";
+  version = "0.1.0";
+
+  src = fetchFromGitHub {
+    owner = "donovanglover";
+    repo = pname;
+    rev = "${version}";
+    hash = lib.fakeSha256;
+  };
+
+  # proxyVendor = true;
+  vendorSha256 = lib.fakeSha256;
+
+  postInstall = ''
+    mkdir -p $out/share/thumbnailers
+    substituteAll ${./go.thumbnailer} $out/share/thumbnailers/go.thumbnailer
+  '';
+
+  meta = with lib; {
+    description = "A cover thumbnailer written in Go for performance and reliability.";
+    homepage = "https://github.com/donovanglover/go-thumbnailer";
+    license = licenses.mit;
+    maintainers = [ ];
+  };
+}

applications/thunar/go-thumbnailer/go.thumbnailer

@@ -0,0 +1,3 @@
+[Thumbnailer Entry]
+Exec=go-thumbnailer %s %i %o
+MimeType=inode/directory