feat: add harpoon

lua/custom/plugins/harpoon.lua

@@ -0,0 +1,23 @@
+return {
+  'ThePrimeagen/harpoon',
+  config = function()
+    local mark = require 'harpoon.mark'
+    local ui = require 'harpoon.ui'
+
+    vim.keymap.set('n', '<leader>a', mark.add_file)
+    vim.keymap.set('n', '<C-e>', ui.toggle_quick_menu)
+
+    vim.keymap.set('n', '<C-h>', function()
+      ui.nav_file(1)
+    end)
+    vim.keymap.set('n', '<C-t>', function()
+      ui.nav_file(2)
+    end)
+    vim.keymap.set('n', '<C-n>', function()
+      ui.nav_file(3)
+    end)
+    vim.keymap.set('n', '<C-s>', function()
+      ui.nav_file(4)
+    end)
+  end,
+}