use oil instead of neotree

lua/plugins/oil.lua

@@ -0,0 +1,10 @@
+return {
+  'stevearc/oil.nvim',
+  ---@module 'oil'
+  ---@type oil.SetupOpts
+  opts = {},
+  -- Optional dependencies
+  dependencies = { { "nvim-mini/mini.icons", opts = {} } },
+  -- Lazy loading is not recommended because it is very tricky to make it work correctly in all situations.
+  lazy = false,
+}