add nvim-config-sync plugin

lua/plugins/nvim-config-sync.lua

+return {
+  "trdd/nvim-config-sync",
+  lazy = false,
+  config = function()
+    require("nvim-config-sync").setup({
+      commit_message = "Update nvim config from Thinkpad", -- You can customize this message
+    })
+  end,
+}