protozero: add changelog URLs

pkgs/development/libraries/protozero/default.nix

@@ -17,6 +17,10 @@ stdenv.mkDerivation rec {
     description = "Minimalistic protocol buffer decoder and encoder in C++";
     homepage = "https://github.com/mapbox/protozero";
     license = with licenses; [ bsd2 asl20 ];
+    changelog = [
+      "https://github.com/mapbox/protozero/releases/tag/v${version}"
+      "https://github.com/mapbox/protozero/blob/v${version}/CHANGELOG.md"
+    ];
     maintainers = with maintainers; [ das-g ];
   };
 }