notable: use .desktop file from AppImage

pkgs/applications/misc/notable/default.nix

···
 let
   pname = "notable";
   version = "1.8.4";
-in
-appimageTools.wrapType2 rec {
+  sha256 = "0rvz8zwsi62kiq89pv8n2wh9h5yb030kvdr1vf65xwqkhqcrzrby";
+
   name = "${pname}-${version}";
+
   src = fetchurl {
     url = "https://github.com/notable/notable/releases/download/v${version}/Notable-${version}.AppImage";
-    sha256 = "0rvz8zwsi62kiq89pv8n2wh9h5yb030kvdr1vf65xwqkhqcrzrby";
+    inherit sha256;
+  };
+
+  appimageContents = appimageTools.extract {
+    inherit name src;
   };
 
+in
+appimageTools.wrapType2 rec {
+
+  inherit name src;
+
   profile = ''
     export LC_ALL=C.UTF-8
     export XDG_DATA_DIRS=${gsettings-desktop-schemas}/share/gsettings-schemas/${gsettings-desktop-schemas.name}:${gtk3}/share/gsettings-schemas/${gtk3.name}:$XDG_DATA_DIRS
···
 
   multiPkgs = null; # no 32bit needed
   extraPkgs = p: (appimageTools.defaultFhsEnvArgs.multiPkgs p) ++ [ p.at-spi2-atk p.at-spi2-core ];
-  extraInstallCommands = "mv $out/bin/{${name},${pname}}";
+  extraInstallCommands = ''
+    mv $out/bin/{${name},${pname}}
+    install -m 444 -D ${appimageContents}/notable.desktop $out/share/applications/notable.desktop
+    install -m 444 -D ${appimageContents}/usr/share/icons/hicolor/1024x1024/apps/notable.png \
+      $out/share/icons/hicolor/1024x1024/apps/notable.png
+    substituteInPlace $out/share/applications/notable.desktop \
+      --replace 'Exec=AppRun' 'Exec=${pname}'
+  '';
 
   meta = with lib; {
     description = "The markdown-based note-taking app that doesn't suck";