A directory-category for terminal emulators

This is a mostly cosmetical commit, in the sense it doesn't change the contents
of any package, but reorganizes the overall Nixpkgs expressions.

Terminal emulators are an ubiquitous tool for any Unix user; even the beginners
are routinely familiarized to it. And, manifestly, there are many
implementations of terminal emulators out there, from those traditionally made
in C and C++ to those written in Haskell and Go.

Terminal emulators deserve more highlight. This commit does that by creating a
category for them.

pkgs/applications/terminal-emulators/tilda/default.nix

@@ -0,0 +1,41 @@
+{ stdenv, fetchFromGitHub, pkgconfig
+, autoreconfHook, gettext, expat, pcre2
+, libconfuse, vte, gtk
+, makeWrapper }:
+
+with stdenv.lib;
+stdenv.mkDerivation rec {
+
+  pname = "tilda";
+  version = "1.5.2";
+
+  src = fetchFromGitHub {
+    owner = "lanoxx";
+    repo = "tilda";
+    rev = "${pname}-${version}";
+    sha256 = "0psq0f4s0s92bba6wwcf6b0j7i59b76svqxhvpavwv53yvhmmamn";
+  };
+
+  nativeBuildInputs = [ autoreconfHook makeWrapper pkgconfig ];
+  buildInputs = [ gettext pcre2 libconfuse vte gtk ];
+
+  LD_LIBRARY_PATH = "${expat.out}/lib"; # ugly hack for xgettext to work during build
+
+  # The config locking scheme relies on the binary being called "tilda",
+  # (`pgrep -C tilda`), so a simple `wrapProgram` won't suffice:
+  postInstall = ''
+    mkdir $out/bin/wrapped
+    mv "$out/bin/tilda" "$out/bin/wrapped/tilda"
+    makeWrapper "$out/bin/wrapped/tilda" "$out/bin/tilda" \
+        --prefix XDG_DATA_DIRS : "$GSETTINGS_SCHEMAS_PATH"
+  '';
+
+  meta = {
+    description = "A Gtk based drop down terminal for Linux and Unix";
+    homepage = "https://github.com/lanoxx/tilda/";
+    license = licenses.gpl3;
+    maintainers = [ maintainers.AndersonTorres ];
+    platforms = platforms.linux;
+  };
+}
+