my edit so far

init.lua

@@ -156,6 +156,16 @@ vim.opt.cursorline = true
 -- Minimal number of screen lines to keep above and below the cursor.
 vim.opt.scrolloff = 10
 
+-- my settings
+vim.opt.tabstop = 4
+vim.opt.softtabstop = 4
+vim.opt.shiftwidth = 4
+vim.opt.nu = true
+vim.opt.relativenumber = true
+vim.opt.expandtab = true
+vim.opt.smartindent = true
+vim.opt.termguicolors = true
+
 -- [[ Basic Keymaps ]]
 --  See `:help vim.keymap.set()`
 

lua/custom/plugins/init.lua

@@ -2,4 +2,8 @@
 --  I promise not to create any merge conflicts in this directory :)
 --
 -- See the kickstart.nvim README for more information
-return {}
+return {
+  { 'CRAG666/code_runner.nvim', config = true },
+  { 'mbbill/undotree' },
+  vim.keymap.set('n', '<leader><F5>', vim.cmd.UndotreeToggle, { desc = 'UndoTree' }),
+}