add nvim-tree into plugin

lua/plugins/tree.lua

@@ -0,0 +1,11 @@
+return {
+    "nvim-tree/nvim-tree.lua",
+    version = "*",
+    lazy = false,
+    dependencies = {
+      "nvim-tree/nvim-web-devicons",
+    },
+    config = function()
+      require("nvim-tree").setup {}
+    end,
+  }