qnotero: fix desktop file

Signed-off-by: Mathias Sven <[e-mail]>
Co-authored-by: Johannes Jöns <[e-mail]>

pkgs/applications/office/qnotero/default.nix

···
     wrapQtApp "$out"/bin/qnotero
   '';
 
+  postInstall = ''
+    mkdir $out/share
+    mv $out/usr/share/applications $out/share/applications
+
+    substituteInPlace $out/share/applications/qnotero.desktop \
+      --replace "Icon=/usr/share/qnotero/resources/light/qnotero.png" "Icon=qnotero"
+
+    mkdir -p $out/share/icons/hicolor/64x64/apps
+    ln -s $out/usr/share/qnotero/resources/light/qnotero.png \
+      $out/share/icons/hicolor/64x64/apps/qnotero.png
+  '';
+
   # no tests executed
   doCheck = false;