add workspace diagnostics filter for trouble

modules/nixvim/plugins/trouble.nix

@@ -1,9 +1,31 @@
 {
-  plugins.trouble.enable = true;
+  plugins.trouble = {
+    enable = true;
+    settings = {
+      modes = {
+        workspace-diagnostics = {
+          mode = "diagnostics";
+          filter = [{
+            any = [
+              { buf = 0; }
+              {
+                __raw =
+                  ''
+                    function(item)
+                      return item.filename:find((vim.loop or vim.uv).cwd(), 1, true)
+                    end
+                  '';
+              }
+            ];
+          }];
+        };
+      };
+    };
+  };
   keymaps = [
     {
       key = "<leader>xx";
-      action = "<cmd>Trouble diagnostics toggle<CR>";
+      action = "<cmd>Trouble workspace-diagnostics toggle<CR>";
       options = {
         silent = true;
       };