Copy the last tab directory when create a new tab

[qekaqeka]

When I create a new tab, the shell inside it has PWD var set on the directory inside which the kitty was initially opened (usually /home/$USER ), but it would be better to take the PWD from the last used tab, because users usually open kitty by hotkey Ctrl+Alt+T which opens kitty in the home directory, and all tabs start with home directory, however the user usually works in another directory, and the user doesn't want to write "cd " each time the user opens a new tab. So it's more convenient to take the PWD (work directory) value from the last used tab

[kovidgoyal]

map whatever new_tab_with_cwd