Enable default plugins, add toggleterm, harpoon and lazygit

lua/custom/plugins/lazygit.lua

@@ -0,0 +1,7 @@
+return {
+  'kdheepak/lazygit.nvim',
+  -- optional for floating window border decoration
+  dependencies = {
+    'nvim-lua/plenary.nvim',
+  },
+}