Install harpoon.

modules/home-manager/neovim.nix

@@ -1,5 +1,6 @@
 {
   config,
+  pkgs,
   lib,
   ...
 }: {
@@ -136,6 +137,27 @@
               desc = "Open Mini.Files and manage the filesystem.";
             }
           ];
+
+          extraPlugins = with pkgs.vimPlugins; {
+            harpoon = {
+              package = harpoon2;
+              setup = ''
+                local harpoon = require("harpoon")
+
+                -- REQUIRED
+                harpoon:setup()
+                -- REQUIRED
+
+                vim.keymap.set("n", "<leader>a", function() harpoon:list():add() end)
+                vim.keymap.set("n", "<C-e>", function() harpoon.ui:toggle_quick_menu(harpoon:list()) end)
+
+                vim.keymap.set("n", "<C-h>", function() harpoon:list():select(1) end)
+                vim.keymap.set("n", "<C-j>", function() harpoon:list():select(2) end)
+                vim.keymap.set("n", "<C-k>", function() harpoon:list():select(3) end)
+                vim.keymap.set("n", "<C-l>", function() harpoon:list():select(4) end)
+              '';
+            };
+          };
         };
       };
     };