data/fonts: simpler cleanups

pkgs/data/fonts/libre-baskerville/default.nix

@@ -1,22 +1,18 @@
-{ stdenv, fetchFromGitHub }:
+{ stdenv, fetchzip }:
 
-stdenv.mkDerivation rec {
+fetchzip rec {
   name = "libre-baskerville-1.000";
 
-  src = fetchFromGitHub {
-    owner = "impallari";
-    repo = "Libre-Baskerville";
-    rev = "2fba7c8e0a8f53f86efd3d81bc4c63674b0c613f";
-    sha256 = "0i9ra6ip81zzjxl71p8zwa6ymlmkf4yi5ny22vlwx9a53kbf4ifl";
-  };
+  url = https://github.com/impallari/Libre-Baskerville/archive/2fba7c8e0a8f53f86efd3d81bc4c63674b0c613f.zip;
 
-  installPhase = ''
-    mkdir -p $out/share/fonts/truetype
-    mkdir -p $out/share/doc/${name}
-    cp -v *.ttf $out/share/fonts/truetype/
-    cp -v README.md FONTLOG.txt $out/share/doc/${name}
+  postFetch = ''
+    mkdir -p $out/share/{doc,fonts}
+    unzip    -j $downloadedFile \*.ttf                    -d $out/share/fonts/truetype
+    unzip -n -j $downloadedFile \*README.md \*FONTLOG.txt -d "$out/share/doc/${name}"
   '';
 
+  sha256 = "0arlq89b3vmpw3n4wbllsdvqblhz6p09dm19z1cndicmcgk26w2a";
+
   meta = with stdenv.lib; {
     description = "A webfont family optimized for body text";
     longDescription = ''