plugins/utility/harpoon: added harpoon

Harpoon (branch harpoon2) has been added as a plugin.
Set under navigation to allow for more naviation plugins to be added in
the future (set telescope under navigation?).
Basic options and keybinds are included.

modules/plugins/utility/harpoon/config.nix

@@ -0,0 +1,51 @@
+{
+  options,
+  config,
+  lib,
+  ...
+}: let
+  inherit (lib.modules) mkIf;
+  inherit (lib.lists) optionals;
+  inherit (lib.strings) concatStrings;
+  inherit (lib.nvim.binds) pushDownDefault mkKeymap;
+
+  cfg = config.vim.navigation.harpoon;
+
+  keys = cfg.mappings;
+  inherit (options.vim.navigation.harpoon) mappings;
+in {
+  config = mkIf cfg.enable {
+    vim = {
+      startPlugins = ["plenary-nvim"];
+
+      lazy.plugins.harpoon = {
+        package = "harpoon";
+        setupModule = "harpoon";
+        inherit (cfg) setupOpts;
+
+        before = ''
+        '';
+
+        after = ''
+          local harpoon = require("harpoon")
+          harpoon.setup({})
+        '';
+
+        cmd = ["Harpoon"];
+
+        keys = [
+          (mkKeymap "n" keys.markFile "<Cmd>lua require('harpoon'):list():add()<CR>" {desc = mappings.markFile.description;})
+          (mkKeymap "n" keys.listMarks "<Cmd>lua require('harpoon').ui:toggle_quick_menu(require('harpoon'):list())<CR>" {desc = mappings.listMarks.description;})
+          (mkKeymap "n" keys.file1 "<Cmd>lua require('harpoon'):list():select(1)<CR>" {desc = mappings.file1.description;})
+          (mkKeymap "n" keys.file2 "<Cmd>lua require('harpoon'):list():select(2)<CR>" {desc = mappings.file2.description;})
+          (mkKeymap "n" keys.file3 "<Cmd>lua require('harpoon'):list():select(3)<CR>" {desc = mappings.file3.description;})
+          (mkKeymap "n" keys.file4 "<Cmd>lua require('harpoon'):list():select(4)<CR>" {desc = mappings.file4.description;})
+        ];
+      };
+
+      binds.whichKey.register = pushDownDefault {
+        "<leader>a" = "Harpoon Mark";
+      };
+    };
+  };
+}