Add reminder to update VCS ignore settings on upgrading from Godot 3 to Godot 4

tutorials/migrating/upgrading_to_godot_4.rst

@@ -784,3 +784,10 @@ editor is closed.
     Many settings' names and categories have changed since Godot 3.x. Editor settings
     whose name or category has changed won't carry over to Godot 4.0; you will
     have to set their values again.
+
+
+Updating version control settings
+-----------------------
+
+Godot 3.x and 4.0 have entirely different lists of files and folders that should
+be ignored by your :ref:`version control systems <doc_version_control_systems>`.