feat(configs/desktop): add google sans

exprs/google-sans.nix

@@ -0,0 +1,23 @@
+{
+  stdenvNoCC,
+  fetchFromGitHub,
+}:
+stdenvNoCC.mkDerivation {
+  pname = "google-sans";
+  version = "0-unstable-2018-07-18";
+
+  src = fetchFromGitHub {
+    owner = "hprobotic";
+    repo = "Google-Sans-Font";
+    rev = "ce4644946bd4e662fec8cf9736b3f99fefa7d308";
+    hash = "sha256-87dKgkb27+O3Y3qQ203PDY3yLCduvIj7hFfNAV9gLOA=";
+  };
+
+  dontConfigure = true;
+  dontBuild = true;
+
+  installPhase = ''
+    mkdir -p $out/share/fonts/truetype
+    cp *.ttf $out/share/fonts/truetype
+  '';
+}

exprs/overlay.nix

@@ -1,5 +1,6 @@
 final: prev: {
   idea-ultimate-fixed = prev.callPackage ./idea-fixed.nix { };
+  google-sans = prev.callPackage ./google-sans.nix { };
 
   urbackup-client = prev.urbackup-client.overrideAttrs (old: {
     nativeBuildInputs = old.nativeBuildInputs or [ ] ++ [ prev.autoreconfHook ];