add autopair plugin

lua/custom/plugins/autopair.lua

@@ -0,0 +1,15 @@
+return {
+  "windwp/nvim-autopairs",
+  -- Optional dependency
+  dependencies = { 'hrsh7th/nvim-cmp' },
+  config = function()
+    require("nvim-autopairs").setup {}
+    -- If you want to automatically add `(` after selecting a function or method
+    local cmp_autopairs = require('nvim-autopairs.completion.cmp')
+    local cmp = require('cmp')
+    cmp.event:on(
+      'confirm_done',
+      cmp_autopairs.on_confirm_done()
+    )
+  end,
+}