fix(nvim): simplify preview.nvim config

flake.nix

@@ -34,6 +34,16 @@
             pkgs.selene
             pkgs.lua-language-server
           ];
+          okular-wrapped = pkgs.symlinkJoin {
+            name = "okular";
+            paths = [ pkgs.kdePackages.okular ];
+            nativeBuildInputs = [ pkgs.makeWrapper ];
+            postBuild = ''
+              wrapProgram $out/bin/okular \
+                --prefix XDG_DATA_DIRS : "${pkgs.gsettings-desktop-schemas}/share/gsettings-schemas/${pkgs.gsettings-desktop-schemas.name}" \
+                --prefix XDG_DATA_DIRS : "${pkgs.gtk3}/share/gsettings-schemas/${pkgs.gtk3.name}"
+            '';
+          };
         in
         {
           default = pkgs.mkShell {
@@ -51,6 +61,7 @@
               pkgs.mermaid-cli
               pkgs.zathura
               pkgs.sioyek
+              okular-wrapped
             ];
           };
         }