feat: add ability for the tree to change tab

- remove tags file
- open/close the tree on `TabEnter` with the option `g:lua_tree_tab_open`

lua/tree.lua

@@ -24,6 +24,7 @@ end
 function M.close()
   if lib.win_open() then
     lib.close()
+    return true
   end
 end
 
@@ -33,6 +34,17 @@ function M.open()
   end
 end
 
+local winopts = config.window_options()
+function M.tab_change()
+  -- we need defer_fn to make sure we close/open after we enter the tab
+  vim.defer_fn(function()
+    if M.close() then
+      M.open()
+      api.nvim_command('wincmd '..winopts.open_command)
+    end
+  end, 1)
+end
+
 local function gen_go_to(mode)
   local icon_state = config.get_icon_state()
   local flags = mode == 'prev_git_item' and 'b' or ''