add todo highlighting

lua/custom/plugins/todos.lua

@@ -0,0 +1,11 @@
+return {
+  'folke/todo-comments.nvim',
+  requires = 'nvim-lua/plenary.nvim',
+  config = function()
+    require('todo-comments').setup {
+      -- your configuration comes here
+      -- or leave it empty to use the default settings
+      -- refer to the configuration section below
+    }
+  end,
+}