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/havoc/default.nix

@@ -0,0 +1,35 @@
+{ stdenv, fetchFromGitHub
+, pkgconfig, libxkbcommon, wayland, wayland-protocols }:
+
+stdenv.mkDerivation rec {
+
+  pname = "havoc";
+  version = "0.3.1";
+
+  src = fetchFromGitHub {
+    owner = "ii8";
+    repo = pname;
+    rev = version;
+    sha256 = "1g05r9j6srwz1krqvzckx80jn8fm48rkb4xp68953gy9yp2skg3k";
+  };
+
+  nativeBuildInputs = [ pkgconfig ];
+  buildInputs = [ libxkbcommon wayland wayland-protocols ];
+
+  dontConfigure = true;
+
+  installFlags = [ "PREFIX=$$out" ];
+
+  postInstall = ''
+    install -D -m 644 havoc.cfg -t $out/etc/${pname}/
+    install -D -m 644 README.md -t $out/share/doc/${pname}-${version}/
+  '';
+
+  meta = with stdenv.lib; {
+    description = "A minimal terminal emulator for Wayland";
+    homepage = "https://github.com/ii8/havoc";
+    license = with licenses; [ mit publicDomain ];
+    platforms = with platforms; unix;
+    maintainers = with maintainers; [ AndersonTorres ];
+  };
+}