wip: update default settings and add filetree

lua/custom/plugins/filetree.lua

@@ -0,0 +1,15 @@
+-- Unless you are still migrating, remove the deprecated commands from v1.x
+vim.cmd [[ let g:neo_tree_remove_legacy_commands = 1 ]]
+
+return {
+  'nvim-neo-tree/neo-tree.nvim',
+  version = '*',
+  dependencies = {
+    'nvim-lua/plenary.nvim',
+    'nvim-tree/nvim-web-devicons', -- not strictly required, but recommended
+    'MunifTanjim/nui.nvim',
+  },
+  config = function()
+    require('neo-tree').setup {}
+  end,
+}